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1

Magnetic properties of biomineral particles produced by bacteria Klebsiella oxytoca  

NASA Astrophysics Data System (ADS)

Ferrihydrite nanoparticles (2-5 nm in size) produced by bacteria Klebsiella oxytoca in the course of biomineralization of iron salt solutions from a natural medium exhibit unique magnetic properties: they are characterized by both the antiferromagnetic order inherent in a bulk ferrihydrite and the spontaneous magnetic moment due to the decompensation of spins in sublattices of a nanoparticle. The magnetic susceptibility enhanced by the superantiferromagnetism effect and the magnetic moment independent of the magnetic field provide the possibility of magnetically controlling these natural objects. This has opened up the possibilities for their use in nanomedicine and bioengineering. The results obtained from measurements of the magnetic properties of the ferrihydrite produced by Klebsiella oxytoca in its two main crystalline modifications are reported, and the data obtained are analyzed theoretically. This has made it possible to determine numerical values of the magnetic parameters of real biomineral nanoparticles.

Ra?kher, Yu. L.; Stepanov, V. I.; Stolyar, S. V.; Ladygina, V. P.; Balaev, D. A.; Ishchenko, L. A.; Balasoiu, M.

2010-02-01

2

Characterization of bio-synthesized nanoparticles produced by Klebsiella oxytoca  

NASA Astrophysics Data System (ADS)

Structural and morphological properties of biogenic ferrihydrite nanoparticles produced by bacteria Klebsiella oxytoca are investigated. The stability of water dispersions of biomineral particles produced by Klebsiella oxytoca was monitored by UV-Vis spectroscopy. Their chemical composition was determined by FT-IR spectroscopy. The vibrational spectra of biogenic ferrihydrite nanoparticles revealed typical absorption peaks of exopolysaccharides. Morphological analysis based on Raman spectroscopy indicated the presence of exopolysaccharides on the surface as well as inside the pores of the ferrihydrite nanoparticles. Structural investigations of ultrasonic assisted samples of different concentration of water dispersed particles were performed using small angle X-ray scattering analysis. Model calculations and fitting procedures revealed scattering objects of an elongated shape with 6.73±0.16 nm radius of gyration.

Anghel, L.; Balasoiu, M.; Ishchenko, L. A.; Stolyar, S. V.; Kurkin, T. S.; Rogachev, A. V.; Kuklin, A. I.; Kovalev, Yu S.; Raikher, Yu L.; Iskhakov, R. S.; Duca, G.

2012-03-01

3

The nickel resistance determinant cloned from the enterobacterium Klebsiella oxytoca: conjugational transfer, expression, regulation and DNA homologies to various nickel-resistant bacteria.  

PubMed

Klebsiella oxytoca strain CCUG 15788, isolated from a mineral oil emulsion tank in Göteborg, Sweden, was found to be nickel-resistant (tolerating 10 mM NiCl2 in non-complexing mineral-gluconate media; inducible resistance). The nickel resistance determinants were transferred by helper-assisted conjugation to various strains of Escherichia coli and Citrobacter freundii and expressed to between 5 and 10 mM NiCl2. A 4.3 kb HindIII fragment was cloned from the genomic DNA of K. oxytoca. Ligated into the vector pSUP202, the fragment caused constitutive nickel resistance (of up to 3 or 10 mM Ni2+) in various E. coli strains. After cloning into the broad host range vector pVDZ'2 the fragment even expressed low nickel resistance in the transconjugant of Alcaligenes eutrophus AE104. With the 4.3 kb HindIII fragment as a biotinylated DNA probe it was shown by DNA-DNA hybridization that the nickel resistance determinant resides on the chromosome of K. oxytoca and not on its circular plasmid pKO1 (160 kb) or linear plasmid pKO2 (50 kb). Nickel resistance strongly correlated with the presence of the 4.3 kb HindIII fragment in the transconjugants. No homologies were detected when the nickel resistance determinants of other well-known nickel-resistant bacteria, such as A. eutrophus CH34 or A. denitrificans 4a-2, were used as target DNA. Among the 60 strains examined, positive signals only appeared with the 3.1 kb DNA fragment from A. xylosoxydans 31A and the genomic DNA of two enterobacterial strains (5-1 and 5-5) isolated from nickel-rich soil in New Caledonia. PMID:7865994

Stoppel, R D; Meyer, M; Schlegel, H G

1995-01-01

4

A proteomic analysis of Klebsiella oxytoca after exposure to succinonitrile  

Microsoft Academic Search

Succinonitrile, an environmental pollutant, has been proved to be degraded by Klebsiella oxytoca. However, the growth rate of this bacterium was decreased by succinonitrile. The aim of this study is to determine the effects of succinonitrile on the physiological responses of K. oxytoca were investigated. Using two-dimensional polyacrylamide gel electrophoresis (2-DE) and MALDI-TOF-MS, we identified the 7 differentially expressed proteins

Peturs Tang; Jong-Kang Liu; Shu-Min Chou; Lien-I. Hor; Wen-Jen Chen; Ssu Ching Chen

2008-01-01

5

Isolation and characterisation of lytic bacteriophages of Klebsiella pneumoniae and Klebsiella oxytoca.  

PubMed

Klebsiella bacteria have emerged as an increasingly important cause of community-acquired nosocomial infections. Extensive use of broad-spectrum antibiotics in hospitalised patients has led to both increased carriage of Klebsiella and the development of multidrug-resistant strains that frequently produce extended-spectrum ?-lactamases and/or other defences against antibiotics. Many of these strains are highly virulent and exhibit a strong propensity to spread. In this study, six lytic Klebsiella bacteriophages were isolated from sewage-contaminated river water in Georgia and characterised as phage therapy candidates. Two of the phages were investigated in greater detail. Biological properties, including phage morphology, nucleic acid composition, host range, growth phenotype, and thermal and pH stability were studied for all six phages. Limited sample sequencing was performed to define the phylogeny of the K. pneumoniae- and K. oxytoca-specific bacteriophages vB_Klp_5 and vB_Klox_2, respectively. Both of the latter phages had large burst sizes, efficient rates of adsorption and were stable under different adverse conditions. Phages reported in this study are double-stranded DNA bacterial viruses belonging to the families Podoviridae and Siphoviridae. One or more of the six phages was capable of efficiently lysing ~63 % of Klebsiella strains comprising a collection of 123 clinical isolates from Georgia and the United Kingdom. These phages exhibit a number of properties indicative of potential utility in phage therapy cocktails. PMID:23143289

Karumidze, Natia; Kusradze, Ia; Rigvava, Sophio; Goderdzishvili, Marine; Rajakumar, Kumar; Alavidze, Zemphira

2013-03-01

6

First description of KPC-2-producing Klebsiella oxytoca in Brazil.  

PubMed

The present work reports the detection of the first case of nosocomial Klebsiella oxytoca producing class A carbapenemase KPC-2 in Brazil. The isolate KPN106 carried a 65-kb IncW-type plasmid that harbors the blaKPC gene and Tn4401b. Moreover, we detected the presence of a class 1 integron containing a new allele, arr-8, followed by a 5'-truncated dhfrIIIc gene. In view of the recent results, we emphasize the high variability of the bacterial and genetic hosts of this resistance determinant. PMID:23752512

Almeida, Anna C S; Cavalcanti, Felipe L S; Martins, Willames M B; Vilela, Marinalda A; Gales, Ana C; Morais Junior, Marcos A; Morais, Márcia M C

2013-08-01

7

Genetic Control of Nitrogen Assimilation in Klebsiella Oxytoca. (Final Report, June 15, 2001-June 14, 2006).  

National Technical Information Service (NTIS)

Klebsiella oxytoca, an enterobacterium closely related to Escherichia coli and amenable to molecular genetic analysis, is a long-established model organism for studies of bacterial nitrogen assimilation. Our work concerned utilization of purines, nitrogen...

V. Stewart

2006-01-01

8

Klebsiella oxytoca bacteremia causing septic shock in recipients of hematopoietic stem cell transplant: Two case reports  

PubMed Central

Background Klebsiella oxytoca can cause various infectious complications in healthy as well as in immunocompromised individuals. Case Presentations Case 1: A 49 year old female with multiple myeloma received an autologous hematopoietic stem cell transplant in October 2005. Eight days following her autograft she developed septic shock caused by Klebsiella oxytoca bacteremia which was successfully treated with intravenous meropenem and gentamicin. Case 2: A 29 year old female with sickle cell anemia and severe aplastic anemia underwent an allogeneic hematopoietic stem cell transplant in July 2005. Seven months following her unsuccessful allograft, she developed septic shock due to Klebsiella oxytoca bacteremia caused by a urinary tract infection. The septic episode was successfully managed with intravenous meropenem and gentamicin. Both patients were treated at King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia. To our knowledge, they are the first reports of Klebsiella oxytoca bacteremias and septic shocks in hematopoietic stem cell transplant recipients. Conclusion Klebsiella oxytoca should be considered as a possible cause of severe infections in recipients of various forms of hematopoietic stem cell transplantation. However, these infections may be complicated by bacteremias, septic shocks, systemic dysfunctions and even deaths if not managed promptly and appropriately.

Al-Anazi, Khalid A; Al-Jasser, Asma M; Al-Zahrani, Hazza A; Chaudhri, Naem; Al-Mohareb, Fahad I

2008-01-01

9

Genome Sequence of Klebsiella oxytoca M5al, a Promising Strain for Nitrogen Fixation and Chemical Production.  

PubMed

Klebsiella oxytoca is an important microorganism for nitrogen fixation and chemical production. Here, we report an annotated draft genome of K. oxytoca strain M5al that contains 5,256 protein-coding genes and 95 structural RNAs, which provides a genetic basis for a better understanding of the physiology of this species. PMID:23405358

Bao, Guanhui; Zhang, Yanping; Du, Chenyu; Chen, Zugen; Li, Yin; Cao, Zhu'an; Ma, Yanhe

2013-01-01

10

Cytotoxic and Pathogenic Properties of Klebsiella oxytoca Isolated from Laboratory Animals  

PubMed Central

Klebsiella oxytoca is an opportunistic pathogen implicated in various clinical diseases in animals and humans. Studies suggest that in humans K. oxytoca exerts its pathogenicity in part through a cytotoxin. However, cytotoxin production in animal isolates of K. oxytoca and its pathogenic properties have not been characterized. Furthermore, neither the identity of the toxin nor a complete repertoire of genes involved in K. oxytoca pathogenesis have been fully elucidated. Here, we showed that several animal isolates of K. oxytoca, including the clinical isolates, produced secreted products in bacterial culture supernatant that display cytotoxicity on HEp-2 and HeLa cells, indicating the ability to produce cytotoxin. Cytotoxin production appears to be regulated by the environment, and soy based product was found to have a strong toxin induction property. The toxin was identified, by liquid chromatography-mass spectrometry and NMR spectroscopy, as low molecular weight heat labile benzodiazepine, tilivalline, previously shown to cause cytotoxicity in several cell lines, including mouse L1210 leukemic cells. Genome sequencing and analyses of a cytotoxin positive K. oxytoca strain isolated from an abscess of a mouse, identified genes previously shown to promote pathogenesis in other enteric bacterial pathogens including ecotin, several genes encoding for type IV and type VI secretion systems, and proteins that show sequence similarity to known bacterial toxins including cholera toxin. To our knowledge, these results demonstrate for the first time, that animal isolates of K. oxytoca, produces a cytotoxin, and that cytotoxin production is under strict environmental regulation. We also confirmed tilivalline as the cytotoxin present in animal K. oxytoca strains. These findings, along with the discovery of a repertoire of genes with virulence potential, provide important insights into the pathogenesis of K. oxytoca. As a novel diagnostic tool, tilivalline may serve as a biomarker for K oxytoca-induced cytotoxicity in humans and animals through detection in various samples from food to diseased samples using LC-MS/MS. Induction of K. oxytoca cytotoxin by consumption of soy may be in part involved in the pathogenesis of gastrointestinal disease.

Sarkar, Ujjal; Seneviratne, Uthpala; Park, Danny S.; Gamazon, Eric R.; Batchelder, Chara; Cheung, Cheryl; Buckley, Ellen M.; Taylor, Nancy S.; Shen, Zeli; Tannenbaum, Steven R.; Wishnok, John S.; Fox, James G.

2014-01-01

11

Detection and spread of oxa-48-producing Klebsiella oxytoca isolates in Istanbul, Turkey.  

PubMed

Five OXA-48 producing Klebsiella oxytoca strains isolated in April-July 2010 were analyzed. Antibiotic susceptibility tests were performed using disc diffusion method and VITEK 2 system. Carbapenemase activity was investigated using the Modified Hodge test. Beta-lactamase genes were detected by PCR and blaOXA-48 was sequenced. Genetic relatedness between K. oxytoca isolates was investigated by pulse-field gel electrophoresis (PFGE). Carbapenemase activity was detected in 5 isolates by Modified Hodge test. Although all strains were resistant to ertapenem and imipenem, only one strain was also resistant to meropenem. BlaOXA-48 in 4 isolates harbored 2 or 3 other ESBL types, namely, blaTEM, blaSHV, blaCTX-M, or blaVEB. PFGE revealed 3 different pulso-types among the K. oxytoca isolates. The presence of OXA-48 carbapenemase in other species of clinical isolates should also be considered. PMID:24964661

Nazik, Hasan; Aydin, Selda; Albayrak, Rüveyda; Bilgi, Esma A; Yildiz, Ismail; Kuvat, Nuray; Kelesoglu, Fatih M; Kelesoglu, Fatih M; Paka?tiçali, Nagehan; Yilmaz, Fadime; Ongen, Betigül

2014-01-01

12

Antibiotic-associated hemorrhagic colitis caused by cytotoxin-producing Klebsiella oxytoca.  

PubMed

Klebsiella oxytoca was recently described as the causative organism for antibiotic-associated hemorrhagic colitis (AAHC). It is currently not known if this novel gastrointestinal infection exists in children. AAHC is usually preceded by antibiotic treatment with penicillins, which are frequently prescribed for pediatric patients. In contrast to colitis caused by Clostridium difficile, colitis caused by K oxytoca is usually segmental and located predominantly in the right colon. Patients with AAHC typically present with abdominal pain and almost always bloody diarrhea. We present here the case of an adolescent patient who developed acute abdominal pain and bloody diarrhea after antibiotic treatment for acute urinary infection with amoxicillin-clavulanate. Right-sided colitis was verified by abdominal sonography. Stool culture tested negative for common gastrointestinal pathogens but yielded K oxytoca. Toxin production of the isolated strain was verified in a cell-culture assay. Cessation of the causative antibiotic treatment led to rapid improvement and cessation of bloody diarrhea within 3 days. We report here the first (to our knowledge) pediatric case of K oxytoca infection causing AAHC. Establishing the diagnosis of AAHC by culturing K oxytoca and demonstrating right-sided colitis with noninvasive imaging studies might prevent unnecessary invasive procedures in children with bloody diarrhea. PMID:20194278

Hoffmann, K Martin; Deutschmann, Andrea; Weitzer, Christa; Joainig, Martina; Zechner, Ellen; Högenauer, Christoph; Hauer, Almuthe C

2010-04-01

13

Fermentation of cellulose to ethanol by Klebsiella oxytoca containing chromosomally integrated Zymomonas mobilis genes  

Microsoft Academic Search

Complete enzymatic hydrolysis of cellulose to glucose is generally required for efficient fermentation to ethanol. This hydrolysis requires endoglucanase, exoglucanase, and cellobiase. The Gram-negative bacterium, Klebsiella oxytoca, contains the native ability to transport and metabolize cellobiose, minimizing the need for extracellular cellobiase. Strain P2 is a recombinant derivative in which the Zymomonas mobilis pdc and adhB genes have been integrated

Joy B. Doran; L. O. Ingram

1993-01-01

14

Carbapenem-Resistant Strain of Klebsiella oxytoca Harboring Carbapenem-Hydrolyzing  Lactamase KPC2  

Microsoft Academic Search

We investigated a Klebsiella oxytoca isolate demonstrating resistance to imipenem, meropenem, extended- spectrum cephalosporins, and aztreonam. The MICs of both imipenem and meropenem were 32 g\\/ml. The -lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. Isoelectric focusing studies demonstrated five -lactamases with pIs of 8.2 (SHV-46), 6.7 (KPC-2), 6.5 (un- known), 6.4 (probable OXY-2),

Hesna Yigit; Anne Marie Queenan; J. Kamile Rasheed; James W. Biddle; Antonio Domenech-Sanchez; Sebastian Alberti; Karen Bush; Fred C. Tenover

2003-01-01

15

Hydrolytic resolution of ( R, S)-ethyl mandelate in biphasic media via Klebsiella oxytoca hydrolase  

Microsoft Academic Search

A thermally stable Klebsiella oxytoca hydrolase was explored as an enantioselective biocatalyst for the hydrolytic resolution of (R,S)-ethyl mandelate in biphasic media. Effects of various process parameters such as solvent type, temperature, pH, product inhibition, enzyme loading and substrate concentration on the enzyme performance were studied, leading to the high enzyme (S)-enantioselectivity of E=56 at 45°C for the reaction media

Pei-Yun Wang; Shau-Wei Tsai

2005-01-01

16

Effect of IAA produced by Klebsiella oxytoca Rs-5 on cotton growth under salt stress.  

PubMed

Klebsiella oxytoca Rs-5 isolated with ACC (1-aminocyclopropane-1-carboxylate) deaminase activity as the sole nitrogen source could obviously promote cotton seedling growth under salt stress and produce phytohormone indole-3-acetic acid (IAA). The amount of IAA produced by the strain Rs-5 was measured, and the effect of IAA on cotton growth under salt stress was studied. Different treatments were set to treat cotton seeds with fermentation broth containing strain Rs-5 (FB), strain Rs-5, fermentation broth with bacteria removed (FB-NB), fermentation broth without bacteria or IAA (FB-NB-NI) and single IAA solutions (SI) according to the IAA concentration after strain Rs-5 culturing of 48, 72 and 120 h. The germination rate, dry weight, plant height, root length and malondialdehyde (MDA), proline and endogenous IAA content in roots were determined. The results showed that both IAA produced by strain Rs-5 and the strain were effective in promoting cotton growth under salt stress. The growth and ability to resist salt stress of cotton seedlings were increased with the enhancement of IAA concentration. The treatment of FB containing bacteria and IAA at 120 h obtained the best state of cotton growth, when the IAA content was the highest in the fermentation broth (42.14 ?g·L(-1)). The germination rate, dry weight, plant height and root length were increased by 29.4%, 24.3%, 27.2% and 27.2% , respectively, compared to the saline control. The strain Rs-5 and/or IAA could obviously reduce the MDA and proline content and increase the endogenous IAA content in cotton seedlings. However, the efficacy of other components in the fermentation broth was inconspicuous. PMID:23518519

Liu, Yan; Shi, Zaiqiang; Yao, Lixia; Yue, Haitao; Li, Hui; Li, Chun

2013-01-01

17

Characterization of FOX-3, an AmpC-Type Plasmid-Mediated ?-Lactamase from an Italian Isolate of Klebsiella oxytoca  

PubMed Central

Klebsiella oxytoca 1731, which showed a wide spectrum of resistance to ?-lactams, including cefoxitin, was isolated in 1994 from a patient in Genoa, Italy. This strain contained a plasmid-mediated AmpC ?-lactamase with a pI of 7.25. Sequencing of the corresponding DNA of K. oxytoca 1731 revealed 96 and 97% identities of the deduced amino acid sequence with FOX-1 and FOX-2, respectively.

Marchese, Anna; Arlet, Guillaume; Schito, Gian Carlo; Lagrange, Philippe H.; Philippon, Alain

1998-01-01

18

Molecular aspects of high-level resistance to sulbactam-cefoperazone in Klebsiella oxytoca clinical isolates.  

PubMed Central

Nine Klebsiella oxytoca strains which demonstrated resistance to the combination of sulbactam and cefoperazone were isolated from geographically separate hospitals in Japan in 1995. Among them, K. oxytoca SB23 showed high-level resistance to sulbactam-cefoperazone (MIC > 128 micrograms/ml) and aztreonam (MIC, 128 micrograms/ml). The sulbactam-cefoperazone resistance was not transferred from strain SB23 to Escherichia coli CSH2 by conjugation, beta-Lactamase RbiA, produced by strain SB23, was purified, and the molecular mass was estimated to be 29 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Kinetic parameters for RbiA revealed that cefoperazone and aztreonam were hydrolyzed efficiently by this enzyme. Moreover, ceftazidime and imipenem were also hydrolyzed weakly by RbiA, although strain SB23 did not show any resistance to these agents. Clavulanate, sulbactam, and tazobactam failed to block the hydrolysis of cefoperazone by RbiA. The structural gene of RbiA (blaRBI) was cloned and sequenced, and the deduced amino acid sequence of RbiA demonstrated high-level similarities to those of the beta-lactamases found in K. oxytoca D488, E23004, and plasmid-mediated MEN-1, which have been classified into Bush functional group 2be. Although RbiA demonstrates high-level molecular similarity to the enzymes in group 2be, from an enzymological point of view, this enzyme might be differentiated from the enzymes in that group. Hybridization analysis revealed that beta-lactamase genes highly similar to blaRBI were generally encoded on the chromosome of the sulbactam-cefoperazone-resistant clinical isolates of K. oxytoca tested in the study, despite their different derivations. This observation suggests that sulbactam-cefoperazone-resistant A. oxytoca strains which produce RbiA-type beta-lactamases have been proliferating in many hospitals in Japan.

Kimura, K; Arakawa, Y; Ohsuka, S; Ito, H; Suzuki, K; Kurokawa, H; Kato, N; Ohta, M

1996-01-01

19

beta-lactamase gene promoters of 71 clinical strains of Klebsiella oxytoca.  

PubMed Central

beta-Lactamase gene promoters of 45 clinical Klebsiella oxytoca isolates resistant to beta-lactams and exhibiting beta-lactamase hyperproduction differed from those in 26 susceptible strains. Direct sequencing revealed one mutation in either the -10 or -35 conserved sequences: a G-to-A transition of the fifth base (67%) or a G-to-T transversion of the first base of the -10 sequence (27%) or a T-to-A transversion in the fourth base in the -35 sequence (4%). One strain carried both the -10 transition and the -35 transversion.

Fournier, B; Lagrange, P H; Philippon, A

1996-01-01

20

Production of 2,3-butanediol by a low-acid producing Klebsiella oxytoca NBRF4.  

PubMed

2,3-Butanediol (2,3-BDO) is a value-added chemical with great potential for the industrial production of synthetic rubber, plastic and solvent. For microbial production of 2,3-BDO, in this study, Klebsiella oxytoca NBRF4 was constructed by chemical mutation and screening against NaBr, NaBrO(3) and fluoroacetate. Among metabolic enzymes involved in the production of lactate, acetate and 2,3-BDO, K. oxytoca NBRF4 possessed 1.2 times lower specific activities of lactate dehydrogenase and phosphotransacetylase, and 22% higher specific acetoin reductase activity than the K. oxytoca ATCC43863 control strain. A series of batch fermentations in a defined medium and application of a statistical tool of response surface method led to the determination of optimal culture conditions: 10% dissolved oxygen level, pH 4.3 and 38°C. The actual results of batch fermentation at the optimal conditions using 44 g/L glucose were coincident with the predetermined values: 14.4 g/L 2,3-BDO concentration, 0.32 g/g yield. To increase 2,3-BDO titer, fed-batch fermentation of K. oxytoca NBRF4 was performed by an intermittent feeding of 800 g/L glucose to control its concentration around 5-20 g/L in the culture broth. Finally, 34.2g/L 2,3-BDO concentration and 0.35 g/g yield were obtained without organic acid production in 70 hours of the fed-batch culture, which were 2.4 and 1.2 times higher than those of the batch fermentation using 44 g/L glucose. PMID:22989924

Han, Sung-Hyuk; Lee, Jung-Eun; Park, Kyungmoon; Park, Yong-Cheol

2013-01-25

21

[Effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca].  

PubMed

To get the tolerability and consumption of Klebsiella oxytoca on major inhibitors in lignocelluloses hydrolysate, we studied the effect of acetic acid, furfural and 5-hydroxymethylfurfural on production of 2,3-butanediol by Klebsiella oxytoca. The metabolites of furfural and 5-hydroxymethylfurfural were measured. The results show that when acetic acid, furfural and 5-hydroxymethylfurfural was individually added, tolerance threshold for Klebsiella oxytoca was 30 g/L, 4 g/L and 5 g/L, respectively. Acetic acid was likely used as substrate to produce 2,3-butanediol. The yield of 2,3-butanediol increased when acetic acid concentration was lower than 30 g/L. In the fermentation, more than 70% 5-hydroxymethylfurfural was converted to 2,5-furandimethanol. All furfural and the rest of 5-hydroxymethylfurfural were metabolized by Klebsiella oxytoca. It showed that in the detoxification process of 2,3-butanediol production using lignocelluloses hydrolysate, furfural should be given priority to remove and a certain concentration of acetic acid is not need to removal. PMID:23789276

Wu, Jing; Cheng, Keke; Li, Wenying; Feng, Jie; Zhang, Jian'an

2013-03-01

22

Genome Sequence of Klebsiella oxytoca SA2, an Endophytic Nitrogen-Fixing Bacterium Isolated from the Pioneer Grass Psammochloa villosa.  

PubMed

Klebsiella oxytoca strain SA2 is an endophytic nitrogen-fixing bacterium isolated from the pioneer grass Psammochloa villosa, which grows in the moving sand dunes of Ordos Plateau, China. The SA2 genome sequence provides the genetic background for understanding its endophytic lifestyle and survival in association with grass in nitrogen-poor environments. PMID:23950120

Chen, Mingyue; Lin, Li; Zhang, Yanming; Sun, Li; An, Qianli

2013-01-01

23

Cloning, Characterization, and Functional Expression of the Klebsiella oxytoca Xylodextrin Utilization Operon (xynTB) in Escherichia coli  

Microsoft Academic Search

Escherichia coli is being developed as a biocatalyst for bulk chemical production from inexpensive carbohy- drates derived from lignocellulose. Potential substrates include the soluble xylodextrins (xyloside, xylooligo- saccharide) and xylobiose that are produced by treatments designed to expose cellulose for subsequent enzymatic hydrolysis. Adjacent genes encoding xylobiose uptake and hydrolysis were cloned from Klebsiella oxytoca M5A1 and are functionally expressed

Yilei Qian; L. P. Yomano; J. F. Preston; H. C. Aldrich; L. O. Ingram

2003-01-01

24

Epidemiology of Klebsiella oxytoca-associated diarrhea detected by Simmons citrate agar supplemented with inositol, tryptophan, and bile salts.  

PubMed

We studied the clinical and epidemiological characteristics of Klebsiella oxytoca-associated diarrhea in hospitalized patients in Hong Kong. Between 1 November 2009 and 30 April 2011, all inositol-fermenting colonies found on Simmons citrate agar supplemented with inositol, tryptophan, and bile salts (SCITB agar) used for the culturing of diarrheal stool samples were screened by a spot indole test for K. oxytoca. The overall sensitivity of SCITB agar plus the spot indole test (93.3%) for the detection of K. oxytoca in stool samples was superior to that of MacConkey agar (63.3%), while the specificities were 100% and 60.4%, respectively. The former achieved a 23-fold reduction in the workload and cost of subsequent standard biochemical identifications. Cytotoxin production and the clonality of K. oxytoca were determined by a cell culture cytotoxicity neutralization assay using HEp-2 cells and pulsed-field gel electrophoresis (PFGE), respectively. Of 5,581 stool samples from 3,537 patients, K. oxytoca was cultured from 117/5,581 (2.1%) stool samples from 104/3,537 (2.9%) patients. Seventy-six of 104 (73.1%) patients with K. oxytoca had no copathogens in their diarrheal stool samples. Twenty-four (31.6%) of 76 patients carried cytotoxin-producing strains, which were significantly associated with antibiotic therapy after hospital admission (50% versus 21.2%; P = 0.01). Health care-associated diarrhea was found in 44 (42%) of 104 patients with K. oxytoca, but there was no epidemiological linkage suggestive of a nosocomial outbreak, and PFGE showed a diverse pattern. None of the patients with cytotoxin-producing K. oxytoca developed antibiotic-associated hemorrhagic colitis, suggesting that K. oxytoca can cause a mild disease manifesting as uncomplicated antibiotic-associated diarrhea with winter seasonality. PMID:22357507

Cheng, Vincent C C; Yam, Wing-Cheong; Tsang, Lee-Lee; Yau, Miranda C Y; Siu, Gilman K H; Wong, Sally C Y; Chan, Jasper F W; To, Kelvin K W; Tse, Herman; Hung, Ivan F N; Tai, Josepha W M; Ho, Pak-Leung; Yuen, Kwok-Yung

2012-05-01

25

Epidemiology of Klebsiella oxytoca-Associated Diarrhea Detected by Simmons Citrate Agar Supplemented with Inositol, Tryptophan, and Bile Salts  

PubMed Central

We studied the clinical and epidemiological characteristics of Klebsiella oxytoca-associated diarrhea in hospitalized patients in Hong Kong. Between 1 November 2009 and 30 April 2011, all inositol-fermenting colonies found on Simmons citrate agar supplemented with inositol, tryptophan, and bile salts (SCITB agar) used for the culturing of diarrheal stool samples were screened by a spot indole test for K. oxytoca. The overall sensitivity of SCITB agar plus the spot indole test (93.3%) for the detection of K. oxytoca in stool samples was superior to that of MacConkey agar (63.3%), while the specificities were 100% and 60.4%, respectively. The former achieved a 23-fold reduction in the workload and cost of subsequent standard biochemical identifications. Cytotoxin production and the clonality of K. oxytoca were determined by a cell culture cytotoxicity neutralization assay using HEp-2 cells and pulsed-field gel electrophoresis (PFGE), respectively. Of 5,581 stool samples from 3,537 patients, K. oxytoca was cultured from 117/5,581 (2.1%) stool samples from 104/3,537 (2.9%) patients. Seventy-six of 104 (73.1%) patients with K. oxytoca had no copathogens in their diarrheal stool samples. Twenty-four (31.6%) of 76 patients carried cytotoxin-producing strains, which were significantly associated with antibiotic therapy after hospital admission (50% versus 21.2%; P = 0.01). Health care-associated diarrhea was found in 44 (42%) of 104 patients with K. oxytoca, but there was no epidemiological linkage suggestive of a nosocomial outbreak, and PFGE showed a diverse pattern. None of the patients with cytotoxin-producing K. oxytoca developed antibiotic-associated hemorrhagic colitis, suggesting that K. oxytoca can cause a mild disease manifesting as uncomplicated antibiotic-associated diarrhea with winter seasonality.

Cheng, Vincent C. C.; Yam, Wing-Cheong; Tsang, Lee-Lee; Yau, Miranda C. Y.; Siu, Gilman K. H.; Wong, Sally C. Y.; Chan, Jasper F. W.; To, Kelvin K. W.; Tse, Herman; Hung, Ivan F. N.; Tai, Josepha W. M.; Ho, Pak-Leung

2012-01-01

26

Selective production of 2,3-butanediol and acetoin by a newly isolated bacterium Klebsiella oxytoca M1.  

PubMed

A newly isolated bacterium, designated as Klebsiella oxytoca M1, produced 2,3-butanediol (2,3-BDO) or acetoin selectively as a major product depending on temperature in a defined medium. K. oxytoca M1 produced 2,3-BDO mainly (0.32~0.34 g/g glucose) at 30 °C while acetoin was a major product (0.32~0.38 g/g glucose) at 37 °C. To investigate factors affecting product profiles according to temperature, the expression level of acetoin reductase (AR) that catalyzes the conversion of acetoin to 2,3-BDO was analyzed using crude protein extracted from K. oxytoca M1 grown at 30 and 37 °C. The AR expression at 37 °C was 12.8-fold lower than that at 30 °C at the stationary phase and reverse transcription PCR (RT-PCR) analysis of the budC (encoding AR) was also in agreement with the AR expression results. When AR was overexpressed using K. oxytoca M1 harboring pUC18CM-budC, 2,3-BDO became a major product at 37 °C, indicating that the AR expression level was a key factor determining the major product of K. oxytoca M1 at 37 °C. The results in this study demonstrate the feasibility of using K. oxytoca M1 for the production of not only 2,3-BDO but also acetoin as a major product. PMID:23793864

Cho, Sukhyeong; Kim, Kyung Duk; Ahn, Jae-Hyung; Lee, Jinwon; Kim, Seon-Won; Um, Youngsoon

2013-08-01

27

Conversion of xylan to ethanol by ethanologenic strains of Escherichia coli and Klebsiella oxytoca  

SciTech Connect

A two-stage process was evaluated for the fermentation of polymeric feedstocks to ethanol by a single, genetically engineered microorganism. The truncated xylanase gene (xynZ) from the thermophilic bacterium Clostridium thermocellum was fused with the N terminus of lacZ to eliminate secretory signals. This hybrid gene was expressed at high levels in ethanologenic strains of Escherichia coli KO11 and Klebsiella oxytoca M5A1(pLOI555). Large amounts of xylanase (25 to 93 mU/mg of cell protein) accumulated as intracellular products during ethanol production. Cells containing xylanase for saccharification. After cooling, the hydrolysate was fermented to ethanol with the same organism (30C), thereby replenishing the supply of xylanase for a subsequent saccharification. Recombinant E. coli metabolized only xylose, while recombinant K. oxytoca M5A1 metabolized xylose, xylobiose, and xylotriose but not xylotetrose. Derivatives of this latter organism produced large amounts of intracellular xylosidase, and the organism is presumed to transport both xylobiose and xylotriose for intracellular hydrolysis. By using recombinant M5A1, approximately 34% of the maximal theoretical yield of ethanol was obtained from xylan by this two-stage process. The yield appeared to be limited by the digestability of commercial xylan rather than by a lack of sufficient xylanase or by ethanol toxicity. In general form, this two-stage process, which uses a single, genetically engineered microorganism, should be applicable for the production of useful chemicals from a wide range of biomass polymers.

Burchhardt, G.; Ingram, L.O. (Univ. of Florida, Gainesville (United States))

1992-04-01

28

Iron-binding characterization and polysaccharide production by Klebsiella oxytoca strain isolated from mine acid drainage  

PubMed Central

Aims: To investigate Klebsiella oxytoca strain BAS-10 growth on ferric citrate under anaerobic conditions for exopolysaccharide (EPS) production and localization on cell followed by the purification and the EPS determination of the iron-binding stability constant to EPS or biotechnological applications. Methods and Results: Klebsiella oxytoca ferments ferric citrate under anaerobic conditions and produces a ferric hydrogel, whereas ferrous ions were formed in solution. During growth, cells precipitate and a hydrogel formation was observed: the organic material was constituted of an EPS bound to Fe(III) ions, this was found by chemical analyses of the iron species and transmission electron microscopy of the cell cultures. Iron binding to EPS was studied by cyclic voltammetric measurements, either directly on the hydrogel or in an aqueous solutions containing Fe(III)-citrate and purified Fe(III)-EPS. From the voltammetric data, the stability constant for the Fe(III)-EPS complex can be assumed to have values of approx. 1012–1013. It was estimated that this is higher than for the Fe(III)-citrate complex. Conclusions: The production of Fe(III)-EPS under anaerobic conditions is a strategy for the strain to survive in mine drainages and other acidic conditions. This physiological feature can be used to produce large amounts of valuable Fe(III)-EPS, starting from a low cost substrate such as Fe(III)-citrate. Significant and Impact of the Study: The data herein demonstrates that an interesting metal-binding molecule can be produced as a novel catalyst for a variety of potential applications and the EPS itself is a valuable source for rhamnose purification.

Baldi, F; Marchetto, D; Battistel, D; Daniele, S; Faleri, C; De Castro, C; Lanzetta, R

2009-01-01

29

Final Technical Report: Genetic Control of Nitrogen Assimilation in Klebsiella oxytoca.  

SciTech Connect

Klebsiella oxytoca, an enterobacterium closely related to Escherichia coli and amenable to molecular genetic analysis, is a long-established model organism for studies of bacterial nitrogen assimilation. Our work concerned utilization of purines, nitrogen-rich compounds that are widespread in the biosphere. This project began with our observation that molybdenum cofactor (chlorate-resistant) mutants can use (hypo)xanthine as sole nitrogen source (Garzón et al., J. Bacteriol. 174:6298, 1992). Since xanthine dehydrogenase is a molybdoenzyme, Klebsiella must use an alternate route for (hypo)xanthine catabolsim. We identified and characterized a cluster of 22 genes that encode the enzymes, permeases and regulators for utilizing hypoxanthine and xanthine as sole nitrogen source. (Hypoxanthine and xanthine arise from deamination of adenine and guanine, respectively.) Growth and complementation tests with insertion mutants, combined with protein sequence comparisons, allow us to assign probable functions for the products of these genes and to deduce the overall pathway. We present genetic evidence that the first two enzymes for the Klebsiella purine utilization pathway have been recruited from pathways involved in catabolism of aromatic compounds. The first, HxaAB enzyme catalyzing (hypo)xanthine oxidation, is related to well-studied aromatic ring hydroxylating oxygenases such as phthalate dioxygenase. The second, HxbA enzyme catalyzing urate hydroxylation, is related to single-component monooxygenases. Thus, the Klebsiella purine utilization pathway has likely experienced non-orthologous gene displacement, substituting these oxygenases for the conventional enzymes, xanthine dehydrogenase and uricase. We also present evidence that transcription of the hxaAB operon is subject to dual regulation: global general nitrogen regulation (Ntr) through an unknown mechanism, and (hypo)xanthine induction mediated by a LysR-type activator.

Valley Stewart

2007-03-07

30

The Cassettes and 3? Conserved Segment of an Integron from Klebsiella oxytoca Plasmid pACM1  

Microsoft Academic Search

pACM1 is a conjugative multiresistance plasmid from Klebsiella oxytoca that encodes SHV-5 extended-spectrum ?-lactamase (ESBL) and has two integrons. The first is a type I (sul type); the second, detected by hybridization with an intI gene probe, has been putatively identified as a defective type I integron. The cassette region of the first integron has now been fully sequenced and

Karen E. Preston; Christopher C. A. Radomski; Richard A. Venezia

1999-01-01

31

Ethanolic fermentation of sucrose, sugarcane juice and molasses by Escherichia coli strain ko11 and Klebsiella oxytoca strain P2  

Microsoft Academic Search

Escherichia coli KO11 and Klebsiella oxytoca P2 recombinants fermented sucrose to ethanol. In minimal medium with 2% or 12% added sucrose KO11 produced 75% and 41%, respectively, of the maximum theoretical yield (0.54g ethanol\\/g sucrose). In Luria-Bertani (LB) broth with up to 8% sucrose, KO11 presented a 94-96% yield and with 12% sucrose, KO11 presented about 69% yield (44.5g ethanol\\/L).

Gervásio P. da Silva; Elza F. de Araújo; Daison O. Silva; Walter V. Guimarães

2005-01-01

32

Kinetic resolution of ( R, S)-ethyl 2-chloromandelate in biphasic media using hydrolase of Klebsiella oxytoca  

Microsoft Academic Search

For the first time, the hydrolytic resolution of (R,S)-ethyl 2-chloromandelate in biphasic media by using hydrolase of Klebsiella oxytoca as a promising biocatalyst is reported for producing the desired (R)-ethyl 2-chloromandelate as an important intermediate for the synthesis of Clopidogrel. Effects of various operating parameters on the enzyme activity and enantioselectivity were systematically studied, from which the optimal condition of

Pei-Yun Wang; Teh-Liang Chen; Shau-Wei Tsai

2006-01-01

33

The pKO2 Linear Plasmid Prophage of Klebsiella oxytoca  

PubMed Central

Temperate bacteriophages with plasmid prophages are uncommon in nature, and of these only phages N15 and PY54 are known to have a linear plasmid prophage with closed hairpin telomeres. We report here the complete nucleotide sequence of the 51,601-bp Klebsiella oxytoca linear plasmid pKO2, and we demonstrate experimentally that it is also a prophage. We call this bacteriophage ?KO2. An analysis of the 64 predicted ?KO2 genes indicate that it is a fairly close relative of phage N15; they share a mosaic relationship that is typical of different members of double-stranded DNA tailed-phage groups. Although the head, tail shaft, and lysis genes are not recognizably homologous between these phages, other genes such as the plasmid partitioning, replicase, prophage repressor, and protelomerase genes (and their putative targets) are so similar that we predict that they must have nearly identical DNA binding specificities. The ?KO2 virion is unusual in that its phage ?-like tails have an exceptionally long (3,433 amino acids) central tip tail fiber protein. The ?KO2 genome also carries putative homologues of bacterial dinI and umuD genes, both of which are involved in the host SOS response. We show that these divergently transcribed genes are regulated by LexA protein binding to a single target site that overlaps both promoters.

Casjens, Sherwood R.; Gilcrease, Eddie B.; Huang, Wai Mun; Bunny, Kim L.; Pedulla, Marisa L.; Ford, Michael E.; Houtz, Jennifer M.; Hatfull, Graham F.; Hendrix, Roger W.

2004-01-01

34

Effects of nano zero-valent iron on Klebsiella oxytoca and stress response.  

PubMed

Nano zero-valent iron (NZVI) is a new option for contaminated soil and groundwater treatment, despite little is known on their impact on environmental microorganisms. Klebsiella oxytoca K5 strain, isolated from the NZVI-treated soil, was used to investigate the bacterial, phenotypical and molecular response to commercial NZVI exposure. Cytotoxicity assays at three NZVI concentrations (1, 5 and 10 mg mL(-1)) suggested a negligible bacteriostatic effect and the lack of bactericidal effect. Structural changes were analysed by electronic microscopy. Scanning electron microscopy revealed the presence of NZVI around some bacterial cells, but no apparent morphological changes were seen. NZVI attachment to the cell surface was confirmed by transmission electron microscopy, although most of them were not affected. A proteomic approach (two-dimensional electrophoresis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry) was used to investigate NZVI impact. For the first time to our knowledge, results revealed that exposure of a soil bacterium to NZVI resulted in the overproduction of tryptophanase, associated with oxidative stress response. K5 may set up an adaptative stress response involving indole as a signal molecule to inform the bacterial population about environmental changes. These findings would improve knowledge on the molecular mechanisms underlying bacterial response to NZVI exposure. PMID:23893265

Saccà, Maria Ludovica; Fajardo, Carmen; Nande, Mar; Martín, Margarita

2013-11-01

35

Fermentation of crystalline cellulose to ethanol by Klebsiella oxytoca containing chromosomally integrated zymomonas mobilis genes  

SciTech Connect

Complete enzymatic hydrolysis of cellulose to glucose is generally required for efficient fermentation to ethanol. This hydrolysis requires endoglucanase, exoglucanase, and cellobiase. The Gram-negative bacterium, Klebsiella oxytoca, contains the native ability to transport and metabolize cellobiose, minimizing the need for extracellular cellobiase. Strain P2 is a recombinant derivative in which the Zymomonas mobilis pdc and adhB genes have been integrated into the chromosome and expressed, directing the metabolism of pyruvate to ethanol. This organism has been evaluated in simultaneous saccharification and fermentation (SSF) experiments to determine optimal conditions and limits of performance. The temperature was varied between 32 and 40{degree}C over a pH range of 5.0-5.8 with 100 g/L crystalline cellulose (Sigmacell 50, Sigma Chemical Company, St. Louis, MO) as the substrate and commercial cellulase (Spezyme CE, South San Francisco, CA). A broad optimum for SSF was observed, with a pH of 5.2-5.5 and temperatures of 32-35{degree}C, which allowed the production of over 44 g of ethanol/L (81-86% of the maximum theoretical yield). Although the rate of ethanol production increased with cellulase, diminishing improvements were observed at enzyme loadings above 10 filter paper units/g of cellulose. 34 refs., 5 figs., 2 tabs.

Doran, J.B.; Ingram, L.O. [Univ. of Florida, Gainesville, FL (United States)

1993-09-01

36

Characterization of FOX3, an AmpC-Type Plasmid-Mediated bLactamase from an Italian Isolate of Klebsiella oxytoca  

Microsoft Academic Search

Klebsiella oxytoca 1731, which showed a wide spectrum of resistance to b-lactams, including cefoxitin, was isolated in 1994 from a patient in Genoa, Italy. This strain contained a plasmid-mediated AmpC b-lactamase with a pI of 7.25. Sequencing of the corresponding DNA of K. oxytoca 1731 revealed 96 and 97% identities of the deduced amino acid sequence with FOX-1 and FOX-2,

ANNA MARCHESE; GUILLAUME ARLET; GIAN CARLO SCHITO; PHILIPPE H. LAGRANGE; ALAIN PHILIPPON

1998-01-01

37

Differentiation of Raoultella ornithinolytica/planticola and Klebsiella oxytoca clinical isolates by matrix-assisted laser desorption/ionization-time of flight mass spectrometry.  

PubMed

Ninety-nine clinical isolates previously identified as Klebsiella oxytoca were evaluated using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Eight isolates were identified as Raoultella spp., being 5 Raoultella spp. and 3 K. oxytoca, by 16S rRNA sequencing. These isolates were correctly identified by applying the 10% differential rule for the MALDI-TOF MS score values. This approach might be useful to discriminate Raoultella species from K. oxytoca. PMID:23375086

de Jong, Eefje; de Jong, Arjan S; Smidts-van den Berg, Nathalie; Rentenaar, Rob J

2013-04-01

38

Cytotoxic Effects of Klebsiella oxytoca Strains Isolated from Patients with Antibiotic-Associated Hemorrhagic Colitis or Other Diseases Caused by Infections and from Healthy Subjects? †  

PubMed Central

Antibiotic-associated hemorrhagic colitis (AAHC) is associated with Klebsiella oxytoca. This study analyzed whether cytotoxic properties are linked to specific subtypes of K. oxytoca. Klebsiella isolates from stools of AAHC patients, healthy carriers, and diarrhea patients as well as from infections of other organs were investigated. Cytotoxic effects on human epithelial cells were limited to the species K. oxytoca and were not detectable for any other Klebsiella species. Isolates from AAHC patients and from stools showed the highest proportion of cytotoxic strains. Urinary or respiratory tract isolates exhibited no cytotoxicity. Macrorestriction profiling of strains revealed no genetic relationships of AAHC isolates or the cytotoxic phenotype but identified that different K. oxytoca strains with different cytotoxic behaviors may be prevalent in the same AAHC patient. Under laboratory conditions, cytotoxicity was maximally effective after exponential bacterial growth and then declined despite the continued viability of K. oxytoca cells in culture. Given its capacity to induce AAHC and that a high proportion of stool isolates tested cytotoxin positive, we argue that K. oxytoca should be considered an opportunistic pathogen if detected in stools. The ability to induce disease after antibiotic treatment most likely represents an overgrowth of the toxin-producing bacterium due to an alteration of the normal colonic microflora.

Joainig, Martina M.; Gorkiewicz, Gregor; Leitner, Eva; Weberhofer, Paul; Zollner-Schwetz, Ines; Lippe, Irmgard; Feierl, Gebhard; Krause, Robert; Hinterleitner, Thomas; Zechner, Ellen L.; Hogenauer, Christoph

2010-01-01

39

Cytotoxic effects of Klebsiella oxytoca strains isolated from patients with antibiotic-associated hemorrhagic colitis or other diseases caused by infections and from healthy subjects.  

PubMed

Antibiotic-associated hemorrhagic colitis (AAHC) is associated with Klebsiella oxytoca. This study analyzed whether cytotoxic properties are linked to specific subtypes of K. oxytoca. Klebsiella isolates from stools of AAHC patients, healthy carriers, and diarrhea patients as well as from infections of other organs were investigated. Cytotoxic effects on human epithelial cells were limited to the species K. oxytoca and were not detectable for any other Klebsiella species. Isolates from AAHC patients and from stools showed the highest proportion of cytotoxic strains. Urinary or respiratory tract isolates exhibited no cytotoxicity. Macrorestriction profiling of strains revealed no genetic relationships of AAHC isolates or the cytotoxic phenotype but identified that different K. oxytoca strains with different cytotoxic behaviors may be prevalent in the same AAHC patient. Under laboratory conditions, cytotoxicity was maximally effective after exponential bacterial growth and then declined despite the continued viability of K. oxytoca cells in culture. Given its capacity to induce AAHC and that a high proportion of stool isolates tested cytotoxin positive, we argue that K. oxytoca should be considered an opportunistic pathogen if detected in stools. The ability to induce disease after antibiotic treatment most likely represents an overgrowth of the toxin-producing bacterium due to an alteration of the normal colonic microflora. PMID:20053860

Joainig, Martina M; Gorkiewicz, Gregor; Leitner, Eva; Weberhofer, Paul; Zollner-Schwetz, Ines; Lippe, Irmgard; Feierl, Gebhard; Krause, Robert; Hinterleitner, Thomas; Zechner, Ellen L; Högenauer, Christoph

2010-03-01

40

Complete sequences of two plasmids in a blaNDM-1-positive Klebsiella oxytoca isolate from Taiwan.  

PubMed

Genetic determinants of a bla(NDM-1)-positive, multidrug-resistant bacterial isolate that caused active infection was investigated by DNA sequencing. Two plasmids, pKOX_NDM1 and pKOX-R1, were identified for the Klebsiella oxytoca strain E718. Sequence annotation revealed a bla(NDM-1) gene in pKOX_NDM1 and two extended-spectrum ?-lactamase producers (bla(CTX-M-3) and blaSHV-12) and a wide array of resistance genes in pKOX-R1. These findings highlight the difficulty in treating multidrug-resistant bacterial infections and the potential danger of emerging resistant enterobacteria. PMID:23752513

Huang, Tzu-Wen; Wang, Jann-Tay; Lauderdale, Tsai-Ling; Liao, Tsai-Lien; Lai, Jui-Fen; Tan, Mei-Chen; Lin, Ann-Chi; Chen, Ying-Tsong; Tsai, Shih-Feng; Chang, Shan-Chwen

2013-08-01

41

The Periplasmic Cyclodextrin Binding Protein CymE from Klebsiella oxytoca and Its Role in Maltodextrin and Cyclodextrin Transport  

Microsoft Academic Search

Klebsiella oxytoca M5a1 has the capacity to transport and to metabolize a-, b- and g-cyclodextrins. Cyclo- dextrin transport is mediated by the products of the cymE, cymF, cymG, cymD, and cymA genes, which are functionally homologous to the malE, malF, malG, malK, and lamB gene products of Escherichia coli. CymE, which is the periplasmic binding protein, has been overproduced and

MARKUS PAJATSCH; MARIA GERHART; RALF PEIST; REINHOLD HORLACHER; WINFRIED BOOS; AUGUST BOCK

1998-01-01

42

Biodegradation of the organochlorine insecticide, endosulfan, and the toxic metabolite, endosulfan sulfate, by Klebsiella oxytoca KE-8.  

PubMed

Biodegradation of endosulfan, a chlorinated cyclodiene insecticide, is generally accompanied by production of the more toxic and more persistent metabolite, endosulfan sulfate. Since our reported endosulfan degrader, Klebsiella pneumoniae KE-1, failed to degrade endosulfan sulfate, we tried to isolate an endosulfan sulfate degrader from endosulfan-polluted soils. Through repetitive enrichment and successive subculture using mineral salt medium containing endosulfan or endosulfan sulfate as the sole source of carbon and energy, we isolated a bacterium capable of degrading endosulfan sulfate as well as endosulfan. The bacterium KE-8 was identified as Klebsiella oxytoca from the results of 16S rDNA sequence analysis. In biodegradation assays with KE-8 using mineral salt medium containing endosulfan (150 mg l(-1)) or endosulfan sulfate (173 mg l(-1)), the biomass was rapidly increased to an optical density at 550 nm of 1.9 in 4 days and the degradation constants for alpha- and beta-endosulfan, and endosulfan sulfate were 0.3084, 0.2983 and 0.2465 day(-1), respectively. Analysis of the metabolites further suggested that K. oxytoca KE-8 has high potential as a biocatalyst for bioremediation of endosulfan and/or endosulfan sulfate. PMID:15700124

Kwon, Gi-Seok; Sohn, Ho-Yong; Shin, Kee-Sun; Kim, Eungbin; Seo, Bu-Il

2005-06-01

43

Comparative In Vitro Activities of Ciprofloxacin, Clinafloxacin, Gatifloxacin, Levofloxacin, Moxifloxacin, and Trovafloxacin against Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes Clinical Isolates with Alterations in GyrA and ParC Proteins  

Microsoft Academic Search

The in vitro activities of ciprofloxacin, clinafloxacin, gatifloxacin, levofloxacin, moxifloxacin, and trovafloxa- cin were tested against 72 ciprofloxacin-resistant and 28 ciprofloxacin-susceptible isolates of Klebsiella pneu- moniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes. Irrespective of the alterations in GyrA and ParC proteins, clinafloxacin exhibited greater activity than all other fluoroquinolones tested against K. pneumoniae and E. aerogenes.

SYLVAIN BRISSE; DANA MILATOVIC; AD C. FLUIT; JAN VERHOEF; NELE MARTIN; SYBILLE SCHEURING; KARL KOHRER; FRANZ-JOSEF SCHMITZ

1999-01-01

44

Genotypes of Klebsiella oxytoca isolates from patients with nosocomial pneumonia are distinct from those of isolates from patients with antibiotic-associated hemorrhagic colitis.  

PubMed

Klebsiella oxytoca acts as a pathobiont in the dysbiotic human intestinal microbiota, causing antibiotic-associated hemorrhagic colitis (AAHC), but it also infects other organs, resulting in pneumonia and urinary tract and skin infections. The virulence of K. oxytoca is still poorly understood. The production of a specific cytotoxin has been linked to AAHC pathogenesis. To investigate the clonal relationships of K. oxytoca with regard to clinical origin and virulence attributes, we established a multilocus sequence typing (MLST) method and analyzed 74 clinical K. oxytoca isolates from asymptomatic carriers and patients with AAHC, respiratory infections, and other infections. The isolates were phenotypically characterized, typed, and compared phylogenetically based on the sequences of seven housekeeping genes. MLST analysis yielded 60 sequence types, 12 of which were represented by more than one isolate. The phylogenetic tree distinguished clusters of K. oxytoca isolates between patients with AAHC and those with respiratory infections. Toxin-positive and -negative strains were observed within one sequence type. Our findings indicate that AAHC isolates share a genetic background. Interestingly, K. oxytoca isolates from nosocomial pneumonia showed a different genetic clustering, suggesting that these strains do not originate from the intestines or that they are specialized for respiratory tract colonization. Our results further indicate a polyphyletic origin and possible horizontal transfer of the genes involved in K. oxytoca cytotoxin production. This work provides evidence that K. oxytoca isolates colonizing the two main clinically relevant habitats (lower gastrointestinal [GI] tract and respiratory tract) of the human host are genetically distinct. Applications of this MLST analysis should help clarify the sources of nosocomial infections. PMID:24599976

Herzog, Kathrin A T; Schneditz, Georg; Leitner, Eva; Feierl, Gebhard; Hoffmann, Karl Martin; Zollner-Schwetz, Ines; Krause, Robert; Gorkiewicz, Gregor; Zechner, Ellen L; Högenauer, Christoph

2014-05-01

45

Screening and confirmatory testing for extended spectrum ?-lactamases (ESBL) in Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca clinical isolates  

Microsoft Academic Search

Escherichia coli and Klebsiella spp. were screened for ESBL based on routine susceptibility testing results. Isolates with intermediate or resistant susceptibilities for extended spectrum cephalosporins or aztreonam were reported as probable ESBL producers. By using the NCCLS proposed ESBL confirmatory method, we tested 61 screen-positive isolates from 42 patients, 30 randomly selected susceptible isolates, and 12 isolates with previously characterized

Emilia Hadziyannis; Marion Tuohy; Linda Thomas; Gary W. Procop; John A. Washington; Geraldine S. Hall

2000-01-01

46

Cloning and construction of recombinant palI gene from Klebsiella oxytoca on pET-32b into E. coli BL21 (DE3) pLysS for production of isomaltulose, a new generation of sugar  

NASA Astrophysics Data System (ADS)

Klebsiella oxytoca produces sucrose isomerase which catalyses the conversion of sucrose to isomaltulose, a new generation of sugar. From the previous study, palI gene from Klebsiella oxytoca was succesfully isolated from sapodilla fruit (Manilkara zapota). The full-length palI gene sequence of Klebsiella oxytoca was cloned in E. coli DH5?. The deduced amino acid sequence shows 498 residues which includes conserved motif for sucrose isomerisation 325RLDRD329 and 97% identical to palI gene from Klebsiella sp. LX3 (GenBank:AAK82938.1). This fragment was succesfullly ligated into the expression vector pET-32b using overlap-extension PCR and cloned in Escherichia coli BL21 (DE3) pLysS. DNA sequencing result shows that palI gene of Klebsiella oxytoca was inserted in-frame in pET-32b. This is the first report on cloning of palI gene from Klebsiella oxytoca.

Moeis, Maelita R.; Berlian, Liska; Suhandono, Sony; Prima, Alex; Komalawati, Eli; Kristianti, Tati

2014-03-01

47

Influences and mechanisms of surfactants on pyrene biodegradation based on interactions of surfactant with a Klebsiella oxytoca strain.  

PubMed

Surfactant-enhanced bioremediation has been proposed as a promising technology for the treatment of organic polluted soils; however its application has been hindered by the controversial influences and mechanisms of surfactants on the biodegradation of hydrophobic organic compounds. To address this problem, effects of five surfactants on the sorption and biodegradation of pyrene by Klebsiella oxytoca PYR-1, as well as their interactions with bacterial cell surface and membrane lipids were investigated. We found that surfactants enhanced or inhibited pyrene biodegradation depending on their effects on the sorption of pyrene onto bacterial cell, which occurred mainly through modifying cell surface hydrophobicity (such as Tween series surfactants) or disrupting bacterial membrane (such as Triton X-100), respectively. A relatively high positive correlation (P<0.0001) was observed between biodegradation promotion (Bs/B0) and enhancement of sorption coefficients (Kd,s(?)/Kd,0(?)) for pyrene in the presence of surfactant, indicating that surfactant-induced sorption played the dominant role during pyrene biodegradation. PMID:23751486

Zhang, Dong; Zhu, Lizhong; Li, Feng

2013-08-01

48

Wastewater drainage system as an occult reservoir in a protracted clonal outbreak due to metallo-?-lactamase-producing Klebsiella oxytoca.  

PubMed

We describe the epidemiology of a protracted nosocomial clonal outbreak due to multidrug-resistant IMP-8 producing Klebsiella oxytoca (MDRKO) that was finally eradicated by removing an environmental reservoir. The outbreak occurred in the ICU of a Spanish hospital from March 2009 to November 2011 and evolved over four waves. Forty-two patients were affected. First basic (active surveillance, contact precautions and reinforcement of surface cleaning) and later additional control measures (nurse cohorting and establishment of a minimum patient/nurse ratio) were implemented. Screening of ICU staff was repeatedly negative. Initial environmental cultures, including dry surfaces, were also negative. The above measures temporarily controlled cross-transmission but failed to eradicate the epidemic MDRKO strain that reappeared two weeks after the last colonized patients in waves 2 and 3 had been discharged. Therefore, an occult environmental reservoir was suspected. Samples from the drainpipes and traps of a sink were positive; removal of the sink reduced the rate number but did not stop new cases that clustered in a cubicle whose horizontal drainage system was connected with the eliminated sink. The elimination of the horizontal drainage system finally eradicated the outbreak. In conclusion, damp environmental reservoirs (mainly sink drains, traps and the horizontal drainage system) could explain why standard cross-transmission control measures failed to control the outbreak; such reservoirs should be considered even when environmental cultures of surfaces are negative. PMID:23829434

Vergara-López, S; Domínguez, M C; Conejo, M C; Pascual, Á; Rodríguez-Baño, J

2013-11-01

49

Dissemination of Clinical Isolates of Klebsiella oxytoca Harboring CMY-31, VIM-1, and a New OXY-2-Type Variant in the Community ?  

PubMed Central

The aim of the present study was to investigate the epidemiological link of multidrug-resistant Klebsiella oxytoca isolates causing community-onset infections among patients attending our outpatient department and to investigate the underlying resistance mechanisms. The isolates were tested by agar dilution MICs, phenotypic carbapenemase testing, enterobacterial repetitive intergenic consensus-PCR, and pulsed-field gel electrophoresis (PFGE). PCR assays and nucleotide sequencing were employed for the identification of bla gene types and the mapping of the integron-containing metallo-?-lactamase (MBL) gene. During the study period (January 2005 to April 2007), nine broad-spectrum cephalosporin-resistant K. oxytoca clinical isolates were prospectively collected from separate outpatients with urinary tract infections. In all cases, the patients had been hospitalized or exposed to health care facilities during the preceding year. Molecular typing revealed that all isolates belonged to the same K. oxytoca clonal type, which contained five PFGE subtypes. A novel chromosomal OXY-2 ?-lactamase type variant (OXY-2-9) was detected in all isolates, but no mutations in the promoter region justifying blaOXY gene overproduction were detected. In addition, all isolates harbored the plasmidic CMY-31 (LAT-4) AmpC cephalosporinase, while three of them harbored VIM-1 MBL in a class 1 integron structure. This is the first study to present the dissemination in the community of multidrug-resistant K. oxytoca isolates causing extrahospital infections.

Tsakris, Athanassios; Poulou, Aggeliki; Markou, Fani; Pitiriga, Vassiliki; Piperaki, Evangelia-Theophano; Kristo, Ioulia; Pournaras, Spyros

2011-01-01

50

Evaluation of the Clinical and Laboratory Standards Institute phenotypic confirmatory test to detect the presence of extended-spectrum ?-lactamases from 4005 Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus mirabilis isolates.  

PubMed

A subset of Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae and Proteus mirabilis isolates collected for the Study for Monitoring Antimicrobial Resistance Trends that were positive for the Clinical and Laboratory Standards Institute (CLSI) extended-spectrum ?-lactamase (ESBL) phenotypic confirmatory test (n?=?3245) or had an ertapenem MIC of ?0.5 µg ml(-1) (n?=?293), or both (n?=?467), were analysed for ESBL genes. Most ESBL phenotype E. coli or K. pneumoniae possessed an ESBL gene (95.8 and 88.4?%, respectively), and this was 93.1?% if carbapenem-non-susceptible K. pneumoniae were removed. This rate was lower for P. mirabilis (73.4?%) and K. oxytoca (62.5?%). Virtually all ESBL-positive isolates (99.5?%) were cefotaxime non-susceptible [CLSI or European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints)]. Fewer isolates (82?%) were ceftazidime non-susceptible (CLSI breakpoints). In addition, 21.1?% of E. coli, 25?% of K. oxytoca and 78.7?% of P. mirabilis isolates were ceftazidime susceptible but ESBL positive. This suggests that CLSI breakpoints for ceftazidime are too high to detect ESBLs. The lower EUCAST breakpoints detected ESBLs in E. coli and K. oxytoca better, but 59.6?% of ESBL-positive isolates of P. mirabilis were ceftazidime susceptible. For isolates with ertapenem MICs ?0.5 µg ml(-1), more accurate ESBL phenotype analysis was observed for E. coli and K. pneumoniae (sensitivity >95?% for both, specificity 94.4 and 54.1?%, respectively). If carbapenemase-positive K. pneumoniae were excluded, the specificity increased to 78?%. The positive predictive values for the ESBL phenotypic test with E. coli and K. pneumoniae were 97.6 and 81.8?%, respectively, and negative predictive values were 75.9 and 95.2?%, respectively. We therefore suggest that it would be prudent to confirm phenotypic ESBL-positive P. mirabilis, K. pneumoniae and K. oxytoca with molecular analysis. PMID:24478449

Morrissey, Ian; Bouchillon, Samuel K; Hackel, Meredith; Biedenbach, Douglas J; Hawser, Stephen; Hoban, Daryl; Badal, Robert E

2014-04-01

51

General Nitrogen Regulation of Nitrate Assimilation Regulatory Gene nasR Expression in Klebsiella oxytoca M5al  

PubMed Central

Klebsiella oxytoca can assimilate nitrate and nitrite by using enzymes encoded by the nasFEDCBA operon. Expression of the nasF operon is controlled by general nitrogen regulation (Ntr) via the NtrC transcription activator and by pathway-specific nitrate and nitrite induction via the NasR transcription antiterminator. This paper reports our analysis of nasR gene expression. We constructed strains bearing single-copy ?(nasR-lacZ) operon fusions within the chromosomal rhaBAD-rhaSR locus. The expression of ?rhaBS::[?(nasR-lacZ)] operon fusions was induced about 10-fold during nitrogen-limited growth. Induction was reduced in both ntrC and rpoN null mutants, indicating that Ntr control of nasR gene expression requires the NtrC and ?N (?54) proteins. Sequence inspection of the nasR control region reveals an apparent ?N-dependent promoter but no apparent NtrC protein binding sites. Analysis of site-specific mutations coupled with primer extension analysis authenticated the ?N-dependent nasR promoter. Fusion constructs with only about 70 nucleotides (nt) upstream of the transcription initiation site exhibited patterns of ?-galactosidase expression indistinguishable from ?(nasR-lacZ) constructs with about 470 nt upstream. Expression was independent of the Nac protein, implying that NtrC is a direct activator of nasR transcription. Together, these results indicate that nasR gene expression does not require specific upstream NtrC-binding sequences, as previously noted for argT gene expression in Salmonella typhimurium (G. Schmitz, K. Nikaido, and G. F.-L. Ames, Mol. Gen. Genet. 215:107–117, 1988).

Wu, Stephen Qitu; Chai, Weihang; Lin, Janine T.; Stewart, Valley

1999-01-01

52

[Research of indole-3-acetic acid biosynthetic pathway of Klebsiella oxytoca SG-11 by HPLC and GC-MS].  

PubMed

The plant growth promoting bacteria are closely associated to plant. The bacteria are used to adhering to plant rhizoplane, promoting plant growth by fixing nitrogen from atmosphere, secreting stimulating substances or producing antagonistic to plant pathogens. It was indicated that the biological nitrogen fixation played an important role in plant growth promoting function. In fact, it was verified recently by overall research that IAA does it. Therefore research of IAA production and biosynthetic pathway of plant growth-promoting bacteria is much more important. The various ways of IAA production indicated the strong or weak promoting function of bacterium to plants in general. The purpose of this paper is to determine whether IAA exists in cultured medium of Klebsiella axytoca SG-11 and biosynthetic pathway of IAA, in order to opimize cultural conditions for IAA production. Klebsiella axytoca SG-11 is a plant growth promoting bacterium, isolated from rice rhizoplane, which can fix nitrogen. The supernatant of SG-11 cultured medium determined by HPLC showed that 47.4 mg/L of IAA existed in LB medium and 1.2 mg/L of IAA, in basal medium. IAA in metabolite was identified by GC/MS as well. The intermediate determination of tryptamine, indole-3-acetamide, tryptophol and indole-3-acetonitrile indirectly indicated that IAA was biosynthesized in a pathway of indole-3-pyruvic acid. Meanwhile, tryptophol in metabolite of SG-11 was verified by GC/MS. The direct intermediates of indole-3-pyruvic acid and indole-3-acetaldehyde in the pathway can not be determined, because both are unstable under normal condition. As reversible conversion existed between indole-3 pyruvic aldehyde and tryptophol, the presence of tryptophol also proved the pathway of indole-3-pyruvic acid in the synthesis of IAA by Klebsiella axytoca SG-11. The results laid basis for further research of plant growth-promoting function of the bacterium. PMID:12541509

Lü, Z X; Song, W

2000-07-01

53

Prevalence, molecular characterization, and phenotypic confirmation of extended-spectrum beta-lactamases in Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca at the Radboud University Nijmegen Medical Centre in The Netherlands.  

PubMed

The prevalence and molecular types of extended-spectrum beta-lactamases (ESBLs) were determined during a 1-year period in unselected clinical nonduplicate isolates of Escherichia coli (n = 1,738), Klebsiella pneumoniae (n = 436), and Klebsiella oxytoca (n = 208), cultured at the University Medical Centre Nijmegen, The Netherlands. Isolates identified as ESBL producer by the Phoenix automated system were collected prospectively and subjected to molecular analysis for the most common ESBLs TEM, SHV, and CTX-M, as well as OXA and GES. Both the Etest ESBL and double-disk synergy test were performed as confirmatory tests. The estimated prevalence of ESBLs was 2.1% in E. coli, 5.2% in K. pneumoniae, and 2.4% in K. oxytoca. TEM-12 and -26, SHV-5 and -12, and CTX-M groups 1 and 9 were the most frequent ESBLs found. Isolates identified as ESBLs by the Phoenix were confirmed by polymerase chain reaction (PCR) in only 42%. In ESBL PCR-positive E. coli and K. pneumoniae, both confirmatory tests were positive in 95% of the isolates. In 28% of the Etest and 13% of the double-disk synergy test-positive isolates, PCR could not detect any ESBL gene. In these cases, other resistance mechanisms may play a role. Confirmatory tests were unreliable for K. oxytoca. A previously described mutation in the K1 enzyme was detected in one ceftazidime-resistant K. oxytoca. The prevalence of ESBLs in The Netherlands is increasing. The predominant molecular types of ESBLs detected were comparable to other studies. Phoenix ESBL results need to be confirmed as advocated by ESBL detection guidelines. PMID:20001741

Sturm, Patrick D J; Bochum, Els T M; van Mook-Vermulst, Sacha V M; Handgraaf, Cindy; Klaassen, Twan; Melchers, Willem J G

2010-03-01

54

Enumeration, Transport and Survival of Bacteria Attached to Granular Activitated Carbon in Drinking Water.  

National Technical Information Service (NTIS)

The surfaces of granular activated carbon (GAC), sand, and anthracite particles were found to be populated to the same levels with heterotrophic plate count (HPC) bacteria. GAC supported a greater number of Klebsiella oxytoca than the other two filter med...

G. A. McFeters A. K. Camper D. G. Davies S. C. Broadaway M. W. LeChevallier

1985-01-01

55

Evaluation of a recombinant Klebsiella oxytoca strain for ethanol production from cellulose by simultaneous saccharification and fermentation: comparison with native cellobiose-utilising yeast strains and performance in co-culture with thermotolerant yeast and Zymomonas mobilis.  

PubMed

In the simultaneous saccharification and fermentation to ethanol of 100 g l(-1) microcrystalline cellulose, the cellobiose-fermenting recombinant Klebsiella oxytoca P2 outperformed a range of cellobiose-fermenting yeasts used in earlier work, despite producing less ethanol than reported earlier for this organism under similar conditions. The time taken by K. oxytoca P2 to produce up to about 33 g l(-1) ethanol was much less than for any other organism investigated, including ethanol-tolerant strains of Saccharomyces pastorianus, Kluyveromyces marxianus and Zymomonas mobilis. Ultimately, it produced slightly less ethanol (maximum 36 g l(-1)) than these organisms, reflecting its lower ethanol tolerance. Significant advantages were obtained by co-culturing K. oxytoca P2 with S. pastorianus, K. marxianus or Z. mobilis, either isothermally, or in conjunction with temperature-profiling to raise the cellulase activity. Co-cultures produced significantly more ethanol, more rapidly, than either of the constituent strains in pure culture at the same inoculum density. K. oxytoca P2 dominated the early stages of the co-cultures, with ethanol production in the later stages due principally to the more ethanol tolerant strain. The usefulness of K. oxytoca P2 in cellulose simultaneous saccharification and fermentation should be improved by mutation of the strain to increase its ethanol tolerance. PMID:12039532

Golias, Helen; Dumsday, Geoffrey J; Stanley, Grant A; Pamment, Neville B

2002-06-26

56

Effect of pH on the metabolic flux of Klebsiella oxytoca producing 2,3-butanediol in continuous cultures at different dilution rates.  

PubMed

The efficiency of the bioconversion process and the achievable end-product concentration decides the economic feasibility of microbial 2,3-butanediol (2,3-BDO) production. In 2,3-BDO production, optimization of culture condition is required for cell growth and metabolism. Also, the pH is an important factor that influences microbial performance. For different microorganisms and substrates, it has been shown that the distribution of the metabolites in 2,3-BDO fermentation is greatly affected by pH, and the optimum pH for 2,3-BDO production seems dependently linked to the particular strain and the substrate employed. Quantification analysis of intracellular metabolites and metabolic flux analysis (MFA) were used to investigate the effect of pH on the Klebsiella oxytoca producing 2,3-BDO and other organic acids. The main objectives of MFA are the estimation of intracellular metabolic fluxes and the identification of rate-limiting step and the key enzymes. This study was conducted under continuous aerobic conditions at different dilution rates (0.1, 0.2, and 0.3 h(-1)) and different pH values (pH 5.5 and 7.0) for the steady-state experimental data. In order to obtain the flux distribution, the extracellular specific rates were calculated from the experimental data using the metabolic network model of K. oxytoca. Intracellular metabolite concentration profiles were generated using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. PMID:23443450

Park, Changhun; Lu, Mingshou; Yun, Seokhun; Park, Kyungmoon; Lee, Jinwon

2013-06-01

57

Adaptative biochemical pathways and regulatory networks in Klebsiella oxytoca BAS-10 producing a biotechnologically relevant exopolysaccharide during Fe(III)-citrate fermentation  

PubMed Central

Background A bacterial strain previously isolated from pyrite mine drainage and named BAS-10 was tentatively identified as Klebsiella oxytoca. Unlikely other enterobacteria, BAS-10 is able to grow on Fe(III)-citrate as sole carbon and energy source, yielding acetic acid and CO2 coupled with Fe(III) reduction to Fe(II) and showing unusual physiological characteristics. In fact, under this growth condition, BAS-10 produces an exopolysaccharide (EPS) having a high rhamnose content and metal-binding properties, whose biotechnological applications were proven as very relevant. Results Further phylogenetic analysis, based on 16S rDNA sequence, definitively confirmed that BAS-10 belongs to K. oxytoca species. In order to rationalize the biochemical peculiarities of this unusual enterobacteriun, combined 2D-Differential Gel Electrophoresis (2D-DIGE) analysis and mass spectrometry procedures were used to investigate its proteomic changes: i) under aerobic or anaerobic cultivation with Fe(III)-citrate as sole carbon source; ii) under anaerobic cultivations using Na(I)-citrate or Fe(III)-citrate as sole carbon source. Combining data from these differential studies peculiar levels of outer membrane proteins, key regulatory factors of carbon and nitrogen metabolism and enzymes involved in TCA cycle and sugar biosynthesis or required for citrate fermentation and stress response during anaerobic growth on Fe(III)-citrate were revealed. The protein differential regulation seems to ensure efficient cell growth coupled with EPS production by adapting metabolic and biochemical processes in order to face iron toxicity and to optimize energy production. Conclusion Differential proteomics provided insights on the molecular mechanisms necessary for anaeorobic utilization of Fe(III)-citrate in a biotechnologically promising enterobacteriun, also revealing genes that can be targeted for the rational design of high-yielding EPS producer strains.

2012-01-01

58

Metabolic Changes in Klebsiella oxytoca in Response to Low Oxidoreduction Potential, as Revealed by Comparative Proteomic Profiling Integrated with Flux Balance Analysis.  

PubMed

Oxidoreduction potential (ORP) is an important physiological parameter for biochemical production in anaerobic or microaerobic processes. However, the effect of ORP on cellular physiology remains largely unknown, which hampers the design of engineering strategies targeting proteins associated with ORP response. Here we characterized the effect of altering ORP in a 1,3-propanediol producer, Klebsiella oxytoca, by comparative proteomic profiling combined with flux balance analysis. Decreasing the extracellular ORP from -150 to -240 mV retarded cell growth and enhanced 1,3-propanediol production. Comparative proteomic analysis identified 61 differentially expressed proteins, mainly involved in carbohydrate catabolism, cellular constituent biosynthesis, and reductive stress response. A hypothetical oxidoreductase (HOR) that catalyzes 1,3-propanediol production was markedly upregulated, while proteins involved in biomass precursor synthesis were downregulated. As revealed by subsequent flux balance analysis, low ORP induced a metabolic shift from glycerol oxidation to reduction and rebalancing of redox and energy metabolism. From the integrated protein expression profiles and flux distributions, we can construct a rational analytic framework that elucidates how (facultative) anaerobes respond to extracellular ORP changes. PMID:24584239

Zhu, Yan; Li, Dan; Bao, Guanhui; Wang, Shaohua; Mao, Shaoming; Song, Jiangning; Li, Yin; Zhang, Yanping

2014-05-01

59

Saccharification and fermentation of sugar cane bagasse by Klebsiella oxytoca P2 containing chromosomally integrated genes encoding the Zymomonas mobilis ethanol pathway  

SciTech Connect

Pretreatment of sugar cane bagasse is essential for a simultaneous saccharification and fermentation (SSF) process which uses recombinant Klebsiella oxytoca strain P2 and Genencor Spezyme CE. Strain P2 has been genetically engineered to express Zymomonas mobilis genes encoding the ethanol pathway and retains the native ability to transport and metabolize cellobiose (minimizing the need for extracellular cellobiase). In SSF studies with this organism, both the rate of ethanol production and ethanol yield were limited by saccharification at 10 and 20 filter paper units (FPU) g[sup [minus]1] acid-treated bagasse. Dilute slurries of biomass were converted to ethanol more efficiently (over 72% of theoretical yield) in simple batch fermentations than slurries containing high solids, albeit with the production of lower levels of ethanol. With high solids (i.e., 160 g acid-treated bagasse L[sup [minus]1]), a combination of 20 FPU cellulase g[sup [minus]1] bagasse, preincubation under saccharification conditions, and additional grinding (to reduce particle size) were required to produce ca. 40 g ethanol L[sup [minus]1]. Alternatively, almost 40 g ethanol L[sup [minus]1] was produced with 10 FPU cellulase g[sup [minus]1] bagasse by incorporating a second saccharification step (no further enzyme addition) followed by a second inoculation and short fermentation. In this way, a theoretical ethanol yield of over 70% was achieved with the production of 20 g ethanol 800 FPU[sup [minus]1] of commercial cellulase.

Doran, J.B.; Aldrich, H.C.; Ingram, L.O. (Univ. of Florida, Gainesville, FL (United States). Dept. of Microbiology and Cell Science)

1994-06-20

60

Hexavalent molybdenum reduction to mo-blue by a sodium-dodecyl-sulfate-degrading Klebsiella oxytoca strain DRY14.  

PubMed

Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS-) degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v), between 25 and 30?mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5?mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700?nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3?g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant. PMID:24383052

Halmi, M I E; Zuhainis, S W; Yusof, M T; Shaharuddin, N A; Helmi, W; Shukor, Y; Syed, M A; Ahmad, S A

2013-01-01

61

Ethanol production from cellobiose, amorphous cellulose, and crystalline cellulose by recombinant Klebsiella oxytoca containing chromosomally integrated Zymomonas mobilis genes for ethanol production and plasmids expressing thermostable cellulase genes from Clostridium thermocellum.  

PubMed Central

The Zymomonas mobilis genes for ethanol production have been integrated into the chromosome of Klebsiella oxytoca M5A1. The best of these constructs, strain P2, produced ethanol efficiently from cellobiose in addition to monomeric sugars. Utilization of cellobiose and cellotriose by this strain eliminated the requirement for external beta-glucosidase and reduced the amount of commercial cellulase needed to ferment Solka Floc SW40 (primarily crystalline cellulose). The addition of plasmids encoding endoglucanases from Clostridium thermocellum resulted in the intracellular accumulation of thermostable enzymes as coproducts with ethanol during fermentation. The best of these, strain P2(pCT603T) containing celD, was used to hydrolyze amorphous cellulose to cellobiose and produce ethanol in a two-stage process. Strain P2(pCT603T) was also tested in combination with commercial cellulases. Pretreatment of Solka Floc SW40 at 60 degrees C with endoglucanase D substantially reduced the amount of commercial cellulase required to ferment Solka Floc. The stimulatory effect of the endoglucanase D pretreatment may result from the hydrolysis of amorphous regions, exposing additional sites for attack by fungal cellulases. Since endoglucanase D functions as part of a complex in C. thermocellum, it is possible that this enzyme may complex with fungal enzymes or bind cellulose to produce a more open structure for hydrolysis.

Wood, B E; Ingram, L O

1992-01-01

62

ENUMERATION, TRANSPORT AND SURVIVAL OF BACTERIA ATTACHED TO GRANULAR ACTIVITATED CARBON IN DRINKING WATER  

EPA Science Inventory

The surfaces of granular activated carbon (GAC), sand, and anthracite particles were found to be populated to the same levels with heterotrophic plate count (HPC) bacteria. GAC supported a greater number of Klebsiella oxytoca than the other two filter media. In a study of operati...

63

EFFECTS OF VELOCITY ON THE TRANSPORT OF TWO BACTERIA THROUGH SATURATED SAND. GROUND WATER.  

EPA Science Inventory

Transport of the bacteria Klebsiella oxytoca and Burkholderia cepacia G4PR1 (G4PR1) was investigated in column experiments conducted under conditions that allowed us to quantify sorption under a range of ground water velocities. Column experiments (33 mm I.D. X 114 mm long colu...

64

Protective effect of Klebsiella bacteria on lawn grasses under conditions of soil salinization  

NASA Astrophysics Data System (ADS)

The protective effect of the inoculation of lawn grasses grown under conditions of soil salinization with bacteria of the Klebsiella genus ( K. planticola and K. pneumoniae) was demonstrated. It was found that K. pneumoniae improves the plant growth under conditions of a high concentration of sodium chloride. It was also shown that the inoculation of lawn grasses with these bacteria optimizes the morphophysiological parameters of the plants and increases the number of mitoses in the apical parts of the roots, which leads to a less significant decrease in the mitotic index under the impact of salinization. The capacity of K. planticola to penetrate into the plants may favor the activation of protective mechanisms improving the immunological status of the plants and, hence, their tolerance to salinization.

Emtsev, V. T.; Sokolova, A. Ya.; Selitskaya, O. V.

2010-07-01

65

Production of polyhydroxyalkanoates in sucrose-utilizing recombinant Escherichia coli and Klebsiella strains.  

PubMed Central

The cloned poly-3-hydroxybutyrate (PHB) synthesis pathway from Alcaligenes eutrophus has been introduced into sucrose-utilizing strains of Escherichia coli, Klebsiella aerogenes, and Klebsiella oxytoca. The plasmid-borne genes were well expressed in these environments and were able to mediate the production of significant amounts of PHB when the bacteria were grown with sucrose as the sole carbon source. The molecular weight of the PHB polymer made in K. aerogenes and E. coli was approximately 1 x 10(6) to 2 x 10(6). Sucrose uptake in K. aerogenes was measured and found to be similar to that found for other Klebsiella strains, but sucrose uptake in the E. coli strain was not detectable. K. aerogenes is able to utilize sugarcane molasses as the sole carbon source to accumulate PHB at the rate of approximately 1 g of PHB per liter of culture fluid per h. A K. oxytoca fadR strain was able to incorporate 3-hydroxyvalerate into a poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-co-V) polymer to levels as high as 56 mol% when grown in a medium containing propionate. Total PHB-co-V levels could be enhanced by adding propionate at the beginning of stationary phase rather than at the time of inoculation. Images

Zhang, H; Obias, V; Gonyer, K; Dennis, D

1994-01-01

66

Preparation and characterization of vanadia-titania mixed oxide for immobilization of Serratia rubidaea CCT 5732 and Klebsiella marcescens bacteria  

SciTech Connect

Vanadia-titania mixed oxide was synthesized by sol-gel method and characterized by several techniques. Texturally, it is formed by mesopores and presents high-specific surface area and controlled porosity. Scanning electron microscopy revealed that vanadium is homogeneously distributed in the material. Structurally, it was possible to identify characteristic V=O stretching bands by IR. The analysis of X-ray diffraction showed that the material, particularly vanadium, is highly dispersed. Application experiments were carried out through the immobilization of Serratia rubidae CCT 5732 and Klebsiella marcescens bacteria by adsorption on the surface of mixed oxide. The micrographies revealed that the bacteria were adsorbed on the entire support, with average surface densities of 8.55 x 10{sup 11} cells/m{sup 2} (Serratia rubidae CCT 5732) and 3.40 x 10{sup 11} cells/m{sup 2} (K. marcescens)

Saragiotto Colpini, Leda Maria [Departamento de Quimica, Universidade Estadual de Maringa, Av. Colombo 5790, 87020-900 Maringa, PR (Brazil)], E-mail: ledasaracol@yahoo.com.br; Correia Goncalves, Regina A. [Departamento de Farmacia e Farmacologia, Universidade Estadual de Maringa, Av. Colombo 5790, 87020-900 Maringa, PR (Brazil); Goncalves, Jose Eduardo [Centro Universitario de Maringa, Av. Guedner 1610, 87050-390 Maringa, PR (Brazil); Maieru Macedo Costa, Creusa [Departamento de Quimica, Universidade Estadual de Maringa, Av. Colombo 5790, 87020-900 Maringa, PR (Brazil)

2008-08-04

67

Influence of Asellus aquaticus on Escherichia coli, Klebsiella pneumoniae, Campylobacter jejuni and naturally occurring heterotrophic bacteria in drinking water.  

PubMed

Water lice, Asellus aquaticus (isopoda), frequently occur in drinking water distribution systems where they are a nuisance to consumers and water utilities. Whether they are solely an aesthetic problem or also affect the microbial water quality is a matter of interest. We studied the influence of A. aquaticus on microbial water quality in non-chlorinated drinking water in controlled laboratory experiments. Pure cultures of the indicator organisms Escherichia coli and Klebsiella pneumoniae and the pathogen Campylobacter jejuni as well as naturally occurring heterotrophic drinking water bacteria (measured as heterotrophic plate counts, HPC) were investigated in microcosms at 7 °C, containing non-sterilised drinking water, drinking water sediment and A. aquaticus collected from a non-chlorinated ground water based drinking water supply system. Concentrations of E. coli, K. pneumoniae and C. jejuni decreased over time, following a first order decay with half lives of 5.3, 18.4 and 1.3 days, respectively. A. aquaticus did not affect survival of indicators and pathogens substantially whereas HPC were influenced by presence of dead A. aquaticus. Growth rates increased with an average of 48% for bacteria grown on R-2A agar and an average of 83% for bacteria grown on yeast extract agar when dead A. aquaticus were present compared to no and living A. aquaticus present. A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were measured (up to 25 per living and 500 per dead A. aquaticus) and so were A. aquaticus associated heterotrophic bacteria (>1.8*10(4) CFU per living and >6*10(4) CFU per dead A. aquaticus). A. aquaticus did not serve as an optimised habitat that increased survival of indicators and pathogens, since A. aquaticus associated E. coli, K. pneumoniae and C. jejuni were only measured as long as the bacteria were also present in the water and sediment. PMID:22884244

Christensen, Sarah C B; Nissen, Erling; Arvin, Erik; Albrechtsen, Hans-Jørgen

2012-10-15

68

The study of Nickel Resistant Bacteria (NiRB) isolated from wastewaters polluted with different industrial sources  

PubMed Central

Background Pollution due to the heavy metals is a problem that may have negative consequences on the hydrosphere. One of the best procedures in removing the toxic metals from the environment is using metal resistant bacteria. Results In the present study eight nickel resistant bacteria were isolated from industrial wastewaters. Three of them were selected as the most resistant based on their Maximum tolerable concentration (8, 16 and 24 mM Ni2+). Their identification was done according to morphological, biochemical characteristics and 16SrDNA gene sequencing and they were identified as Cupriavidus sp ATHA3, Klebsiella oxytoca ATHA6 and Methylobacterium sp ATHA7. The accession numbers assigned to ATHA3, ATHA6 and ATHA7 strains are JX120152, JX196648 and JX457333 respectively. The Growth rate of the most resistant isolate, Klebsiella oxytoca strain ATHA6, in the presence of Ni2+ and the reduction in Ni2+ concentration was revealed that K oxytoca ATHA6 could decrease 83 mg/mL of nickel from the medium after 3 days. Conclusion It can be concluded that the identified Ni resistant bacteria could be valuable for the bioremediation of Ni polluted waste water and sewage.

2014-01-01

69

Abiotic Process for Fe(II) Oxidation and Green Rust Mineralization Driven by a Heterotrophic Nitrate Reducing Bacteria (Klebsiella mobilis).  

PubMed

Green rusts (GRs) are mixed Fe(II)-Fe(III) hydroxides with a high reactivity toward organic and inorganic pollutants. GRs can be produced from ferric reducing or ferrous oxidizing bacterial activities. In this study, we investigated the capability of Klebsiella mobilis to produce iron minerals in the presence of nitrate and ferrous iron. This bacterium is well-known to reduce nitrate using an organic carbon source as electron donor but is unable to enzymatically oxidize Fe(II) species. During incubation, GR formation occurred as a secondary iron mineral precipitating on cell surfaces, resulting from Fe(II) oxidation by nitrite produced via bacterial respiration of nitrate. For the first time, we demonstrate GR formation by indirect microbial oxidation of Fe(II) (i.e., a combination of biotic/abiotic processes). These results therefore suggest that nitrate-reducing bacteria can potentially contribute to the formation of GR in natural environments. In addition, the chemical reduction of nitrite to ammonium by GR is observed, which gradually turns the GR into the end-product goethite. The nitrogen mass-balance clearly demonstrates that the total amount of ammonium produced corresponds to the quantity of bioreduced nitrate. These findings demonstrate how the activity of nitrate-reducing bacteria in ferrous environments may provide a direct link between the biogeochemical cycles of nitrogen and iron. PMID:24605878

Etique, Marjorie; Jorand, Frédéric P A; Zegeye, Asfaw; Grégoire, Brian; Despas, Christelle; Ruby, Christian

2014-04-01

70

Utility of NCCLS Guidelines for Identifying Extended-Spectrum -Lactamases in Non-Escherichia coli and Non-Klebsiella spp. of Enterobacteriaceae  

Microsoft Academic Search

NCCLS screening and confirmation methods for detecting extended-spectrum -lactamases (ESBLs) apply only to Escherichia coli and Klebsiella spp., yet ESBLs have been found in other members of the family Enterobacteriaceae. We evaluated the effectiveness of NCCLS methods for detecting ESBLs in 690 gram- negative isolates of Enterobacteriaceae that excluded E. coli, Klebsiella pneumoniae, and Klebsiella oxytoca. Isolates were collected between

Mitchell J. Schwaber; Patti M. Raney; J. Kamile Rasheed; James W. Biddle; Portia Williams; John E. McGowan; Fred C. Tenover

2004-01-01

71

Fermentation of polysaccharides by Klebsiella and other facultative bacilli  

SciTech Connect

Fermentations of 10 polysaccharides by species of the family Enterobacteriaceae were examined. Algin, guar, karaya, xanthan, and xylan were not fermented by any of the strains tested. Most of the activity was found in the tribe Klebsielleae. Klebseilla oxytoca fermented amylopectin (97% of the strains studied), carrageenan (100%), inulin (68%), polypectate (100%), and tragacanth (100%). Klebsiella pneumoniae fermented amylopectin (91%), carrageenan (100%), and tragacanth (86%). Carraggeenan was also fermented by Enterobacter aerogenes (100%), Enterobacter agglomerans (63%), Enterobacter cloacae (95%), and pectobacterium (38%). pectobacterium shared polypectate fermentation (100%) with K. oxytoca. With one exception, Serratia strains were negative on all polysaccharides. These results, along with other evidence, indicate that (i) the genus Klebsiella is biochemically the most versatile genus of the tribe, (ii) because of its distinct characteristics, K. oxytoca warrants species designation separate from K. pneumoniae, and (iii) some food additives generally considered indigestible can be metabolized by a few species of facultative bacilli, whereas others appear to be resistant.

Ochuba, G.U.; Von Riesen, V.L.

1980-05-01

72

Relationship between indole production and differentiation of Klebsiella species: indole-positive and -negative isolates of Klebsiella determined to be clonal.  

PubMed Central

Klebsiellae are an important cause of nosocomial infections. The two clinically relevant species, Klebsiella pneumoniae and Klebsiella oxytoca, are differentiated by the ability to produce indole from tryptophan, K. oxytoca being indole positive. We report here the detailed biochemical and molecular analysis of two isolates of Klebsiella, cultured from the same urine specimen, that differed only in their ability to produce indole. The two isolates were identical as determined by ribotyping and pulsed-field gel electrophoresis, and they differed from 10 epidemiologically unrelated strains. Probing with the Escherichia coli tryptophanase operon, tna, revealed seven restriction fragment length polymorphisms (RFLP) among the 12 strains. The two index strains had identical RFLP; no single RFLP could account for all of the indole-positive or -negative strains. Thus, the identification of epidemiologically related strains of Klebsiella differing only in indole production may warrant further examination to determine whether the strains are clonal. Images

Maslow, J N; Brecher, S M; Adams, K S; Durbin, A; Loring, S; Arbeit, R D

1993-01-01

73

Digestion of cellulose and xylan by symbiotic bacteria in the intestine of the Indian flying fox (Pteropus giganteus).  

PubMed

Bats (Order Chiroptera) are a widely distributed group of mammals. Pteropus giganteus belongs to the Suborder Megachiroptera. This bat consumes fruits and leaves as their major food. Cellulose and xylan are the major composition of leaves. As they consume leaves in their diet, their digestive tract must contain cellulolytic and xylanolytic bacteria which help in the digestion of cellulose and xylan. The cellulolytic and xylanolytic bacteria were isolated and screened on Berg's agar containing cellulose and xylan. The bacteria isolated were characterized biochemically and found to be Proteus vulgaris, Proteus mirabilis, Citrobacter freundii, Serratia liquefaciens and Klebsiella oxytoca. These bacteria help in digestion of cellulose and xylan in the diet of the bat, P. giganteus. Here we show that leaves are also used as a carbohydrate source by these bats. An insectivorous bat, Hipposideros fulvus, was used as a control and does not possess cellulolytic and xylanolytic bacteria. PMID:15471682

Prem Anand, A Alwin; Sripathi, K

2004-09-01

74

Identification of Clinical Isolates of Indole-Positive Klebsiella spp., Including Klebsiella planticola, and a Genetic and Molecular Analysis of Their b-Lactamases  

Microsoft Academic Search

In a collection of 43 indole-positive Klebsiella clinical isolates, which were initially identified as Klebsiella oxytoca, there were 18 isolates which exhibited a pattern characteristic of extended-spectrum b-lactamase (ESBL) resistance. This study aimed to confirm their identity by biochemical tests and by PCR and to determine the genetic basis for their resistance to the b-lactams and broad-spectrum cephalosporins. Chro- mosomal

YUE LIU; BRIAN J. MEE; LEIGH MULGRAVE

1997-01-01

75

Surveillance of multidrug resistant uropathogenic bacteria in hospitalized patients in Indian  

PubMed Central

Objective To record surveillance, antibiotic resistance of uropathogens of hospitalized patients over a period of 18 months. Methods Urine samples from wards and cabins were used for isolating urinary tract infection (UTI)-causing bacteria that were cultured on suitable selective media and identified by biochemical tests; and their antibiograms were ascertained by Kirby-Bauer's disc diffusion method, in each 6-month interval of the study period, using 18 antibiotics of five different classes. Results From wards and cabins, 1?245 samples were collected, from which 996 strains of bacteria belonging to 11 species were isolated, during April 2011 to September 2012. Two Gram-positive, Staphylococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis), and nine Gram-negative bacteria, Acinetobacter baumannii, Citrobacter sp., Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were isolated. Both S. aureus and E. faecalis were vancomycin resistant, and resistant-strains of all pathogens increased in each 6-month period of study. Particularly, all Gram-negatives were resistant to nitrofurantoin and co-trimoxazole, the most preferred antibiotics of empiric therapy for UTI. Conclusions Antibiograms of 11 UTI-causing bacteria recorded in this study indicated moderately higher numbers of strains resistant to each antibiotic studied, generating the fear of precipitating fervent episodes in public health particularly with bacteria, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and S. aureus. Moreover, vancomycin resistance in strains of S. aureus and E. faecalis is a matter of concern.

Mishra, Monali Priyadarsini; Debata, Nagen Kumar; Padhy, Rabindra Nath

2013-01-01

76

Bacteria on housefly eggs, Musca domestica, suppress fungal growth in chicken manure through nutrient depletion or antifungal metabolites  

NASA Astrophysics Data System (ADS)

Female houseflies, Musca domestica (Diptera: Muscidae), lay their eggs in ephemeral resources such as animal manure. Hatching larvae compete for essential nutrients with fungi that also colonize such resources. Both the well-known antagonistic relationship between bacteria and fungi and the consistent presence of the bacterium Klebsiella oxytoca on housefly eggs led us to hypothesize (1) that K. oxytoca, and possibly other bacteria on housefly eggs, help curtail the growth of fungal resource competitors and (2) that such fungi indeed adversely affect the development of housefly larvae. Bacteria washed from housefly eggs significantly reduced the growth of fungi in chicken manure. Nineteen bacterial strains and ten fungal strains were isolated from housefly eggs or chicken manure, respectively. Co-culturing each of all the possible bacterium-fungus pairs revealed that the bacteria as a group, but no single bacterium, significantly suppressed the growth of all fungal strains tested. The bacteria's adverse effect on fungi is due to resource nutrient depletion and/or the release of antifungal chemicals. Well-established fungi in resources significantly reduced the number of larval offspring that completed development to adult flies.

Lam, Kevin; Thu, Kelsie; Tsang, Michelle; Moore, Margo; Gries, Gerhard

2009-09-01

77

Metabolic engineering of bacteria for ethanol production  

SciTech Connect

Technologies are available which will allow the conversion of lignocellulose into fuel ethanol using genetically engineered bacteria. Assembling these into a cost-effective process remains a challenge. The authors` work has focused primarily on the genetic engineering of enteric bacteria using a portable ethanol production pathway. Genes encoding Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase have been integrated into the chromosome of Escherichia coli B to produce strain KO11 for the fermentation of hemicellulose-derived syrups. This organism can efficiently ferment all hexose and pentose sugars present in the polymers of hemicellulose. Klebsiella oxytoca M5A1 has been genetically engineered in a similar manner to produce strain P2 for ethanol production from cellulose. This organism has the native ability to ferment cellobiose and cellotriose, eliminating the need for one class of cellulase enzymes. The optimal pH for cellulose fermentation with this organism is near that of fungal cellulases. The general approach for the genetic engineering of new biocatalysts has been most successful with enteric bacteria thus far. However, this approach may also prove useful with gram-positive bacteria which have other important traits for lignocellulose conversion. Many opportunities remain for further improvements in the biomass to ethanol processes.

Ingram, L.O.; Gomez, P.F.; Lai, X.; Moniruzzaman, M.; Wood, B.E.; Yomano, L.P.; York, S.W. [Univ. of Florida, Gainesville, FL (United States). Dept. of Microbiology and Cell Science] [Univ. of Florida, Gainesville, FL (United States). Dept. of Microbiology and Cell Science

1998-04-20

78

Alimentary Tract Bacteria Isolated and Identified with API-20E and Molecular Cloning Techniques from Australian Tropical Fruit Flies, Bactrocera cacuminata and B. tryoni  

PubMed Central

Bacteria were isolated from the crop and midgut of field collected Bactrocera cacuminata (Hering) and Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). Two methods were used, firstly isolation onto two types of bacteriological culture media (PYEA and TSA) and identification using the API-20E diagnostic kit, and secondly, analysis of samples using the 16S rRNA gene molecular diagnostic method. Using the API-20E method, 10 genera and 17 species of bacteria in the family Enterobacteriaceae were identified from cultures growing on the nutrient agar. The dominant species in both the crop and midgut were Citrobacter freundii, Enterobacter cloacae and Klebsiella oxytoca. Providencia rettgeri, Klebsiella pneumoniae ssp ozaenae and Serratia marcescens were isolated from B. tryoni only. Using the molecular cloning technique that is based on 16S rRNA gene sequences, five bacteria classes were dignosed — Alpha-, Beta-, Gamma- and Delta- Proteobacteria and Firmicutes — including five families, Leuconostocaceae, Enterococcaceae, Acetobacteriaceae, Comamonadaceae and Enterobacteriaceae. The bacteria affiliated with Firmicutes were found mainly in the crop while the Gammaproteobacteria, especially the family Enterobacteriaceae, was dominant in the midgut. This paper presents results from the first known application of molecular cloning techniques to study bacteria within tephritid species and the first record of Firmicutes bacteria in these flies.

Thaochan, N.; Drew, R. A. I.; Hughes, J. M.; Vijaysegaran, S.; Chinajariyawong, A.

2010-01-01

79

Comparison of Phoenix and VITEK 2 Extended-Spectrum--Lactamase Detection Tests for Analysis of Escherichia coli and Klebsiella Isolates with Well-Characterized -Lactamases  

Microsoft Academic Search

The VITEK 2 and Phoenix extended-spectrum -lactamase (ESBL) detection systems, which comprise confirmatory tests and expert systems, were evaluated for their ability to discriminate between 102 well- characterized strains of ESBL-positive or -negative Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca. At least 38 distinct ESBLs were included. The strains were chosen to include some known to cause false-positive and false-negative

Kenneth S. Thomson; Nancy E. Cornish; Seong G. Hong; Kim Hemrick; Christian Herdt; Ellen S. Moland

2007-01-01

80

Carbapenemase-producing Enterobacteriaceae in a tertiary hospital in Madrid, Spain: high percentage of colistin resistance among VIM-1-producing Klebsiella pneumoniae ST11 isolates.  

PubMed

Here we describe the carbapenemase genes, genetic relatedness and antimicrobial susceptibility data of 123 carbapenemase-producing Enterobacteriaceae (CPE) clinical isolates recovered from 2010 to 2012, comprising Klebsiella pneumoniae (n = 79), Klebsiella oxytoca (n = 13), Serratia marcescens (n = 14), Enterobacter cloacae (n = 12), Enterobacter asburiae (n = 4) and Enterobacter aerogenes (n = 1). VIM-1 was the most common carbapenemase (n = 101) followed by KPC-2 (n = 19), OXA-48 (n = 2) and IMP-22 (n = 1). Among the K. pneumoniae isolates, nine sequence types (STs) were identified but two clones were dominant: ST11 (54/79) containing mainly VIM-1-producing isolates; and ST101 (13/79) constituted by KPC-2-producing strains. Pulsed-field gel electrophoresis (PFGE) showed a higher genetic diversity among the remaining Enterobacteriaceae. Amikacin and fosfomycin were the most active agents with 82.9% and 80.5% susceptibility, respectively. Non-susceptibility to tigecycline was detected in 36.5% of strains. Overall, colistin resistance was 24.7% and was as high as 47% in Enterobacter spp. An increase in colistin resistance from 13.5% to 31.7% was observed among K. pneumoniae isolates during the study period. Resistance was focused on ST11 since 83.3% of colistin-resistant strains belonged to this clone. The high level of colistin resistance observed in this study is worrying with respect to the already limited therapeutic options for infections caused by multidrug-resistant Gram-negative bacteria. PMID:24657043

Pena, Irene; Picazo, Juan J; Rodríguez-Avial, Carmen; Rodríguez-Avial, Iciar

2014-05-01

81

Antimicrobial and Herbal Drug Resistance in Enteric Bacteria Isolated from Faecal Droppings of Common House Lizard/Gecko (Hemidactylus frenatus).  

PubMed

From 194 faecal dropping samples of common house geckos collected from offices (60), houses (88), integrated farm units (IFS,18) and hostels, guest houses, and dining rooms of different canteen/mess (HGM, 28), 326 bacterial isolates of enteric bacteria belonging to 17 genera and 34 species were detected. Escherichia coli were the most frequently (39) isolated followed by Citrobacter freundii (33), Klebsiella pneumonia (27), Salmonella indica (12), Enterobacter gergoviae (12), and Ent. agglomerans (11). Other important bacteria isolated from gecko droppings were Listonella damsela (2), Raoultella terrigena (3), S. salamae (2), S. houtenae (3), Edwardsiella tarda (4), Edwardsiella hoshinae (1), and Klebsiella oxytoca (2). Of the 223 isolates tested for antimicrobial drug sensitivity, 27 (12.1%) had multiple drug resistance (MDR). None of the salmonellae or edwardsiellae had MDR however, MDR strains were significantly more common among Escherichia spp. (P = 1.9 × 10(-5)) and isolates from IFS units (P = 3.58 × 10(-23)). The most effective herbal drug, Ageratum conyzoides extract, inhibited growth of only 27.8% of strains tested followed by ethanolic extract of Zanthoxylum rhetsa (13.9%), eucalyptus oil (5.4%), patchouli oil (5.4%), lemongrass oil (3.6%), and sandalwood oil (3.1%), and Artemisia vulgaris essential oil (3.1%). PMID:24223595

Singh, Bhoj R; Singh, Vidya; Ebibeni, N; Singh, Raj K

2013-01-01

82

Efficacy of surface disinfectant cleaners against emerging highly resistant gram-negative bacteria  

PubMed Central

Background Worldwide, the emergence of multidrug-resistant gram-negative bacteria is a clinical problem. Surface disinfectant cleaners (SDCs) that are effective against these bacteria are needed for use in high risk areas around patients and on multi-touch surfaces. We determined the efficacy of several SDCs against clinically relevant bacterial species with and without common types of multidrug resistance. Methods Bacteria species used were ATCC strains; clinical isolates classified as antibiotic-susceptible; and multi-resistant clinical isolates from Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens (all OXA-48 and KPC-2); Acinetobacter baumannii (OXA-23); Pseudomonas aeruginosa (VIM-1); and Achromobacter xylosoxidans (ATCC strain). Experiments were carried out according to EN 13727:2012 in quadruplicate under dirty conditions. The five evaluated SDCs were based on alcohol and an amphoteric substance (AAS), an oxygen-releaser (OR), surface-active substances (SAS), or surface-active-substances plus aldehydes (SASA; two formulations). Bactericidal concentrations of SDCs were determined at two different contact times. Efficacy was defined as a log10???5 reduction in bacterial cell count. Results SDCs based on AAS, OR, and SAS were effective against all six species irrespective of the degree of multi-resistance. The SASA formulations were effective against the bacteria irrespective of degree of multi-resistance except for one of the four P. aeruginosa isolates (VIM-1). We found no general correlation between SDC efficacy and degree of antibiotic resistance. Conclusions SDCs were generally effective against gram-negative bacteria with and without multidrug resistance. SDCs are therefore suitable for surface disinfection in the immediate proximity of patients. Single bacterial isolates, however, might have reduced susceptibility to selected biocidal agents.

2014-01-01

83

Analysis of the 16S-23S rRNA Gene Internal Transcribed Spacer Region in Klebsiella Species?  

PubMed Central

The 16S-23S rRNA gene internal transcribed spacer (ITS) regions of Klebsiella spp., including Klebsiella pneumoniae subsp. pneumoniae, Klebsiella pneumoniae subsp. ozaenae, Klebsiella pneumoniae subsp. rhinoscleromatis, Klebsiella oxytoca, Klebsiella planticola, Klebsiella terrigena, and Klebsiella ornithinolytica, were characterized, and the feasibility of using ITS sequences to discriminate Klebsiella species and subspecies was explored. A total of 336 ITS sequences from 21 representative strains and 11 clinical isolates of Klebsiella were sequenced and analyzed. Three distinct ITS types—ITSnone (without tRNA genes), ITSglu [with a tRNAGlu (UUC) gene], and ITSile+ala [with tRNAIle (GAU) and tRNAAla (UGC) genes]—were detected in all species except for K. pneumoniae subsp. rhinoscleromatis, which has only ITSglu and ITSile+ala. The presence of ITSnone in Enterobacteriaceae had never been reported before. Both the length and the sequence of each ITS type are highly conserved within the species, with identity levels from 0.961 to 1.000 for ITSnone, from 0.967 to 1.000 for ITSglu, and from 0.968 to 1.000 for ITSile+ala. Interspecies sequence identities range from 0.775 to 0.989 for ITSnone, from 0.798 to 0.997 for ITSglu, and from 0.712 to 0.985 for ITSile+ala. Regions with significant interspecies variations but low intraspecies polymorphisms were identified; these may be targeted in the design of probes for the identification of Klebsiella to the species level. Phylogenetic analysis based on ITS regions reveals the relationships among Klebsiella species similarly to that based on 16S rRNA genes.

Wang, Min; Cao, Boyang; Yu, Qunfang; Liu, Lei; Gao, Qili; Wang, Lei; Feng, Lu

2008-01-01

84

SUSCEPTIBILITY OF CHEMOSTAT-GROWN 'YERSINIA ENTEROCOLITICA' AND 'KLEBSIELLA PNEUMONIAE' TO CHLORINE DIOXIDE  

EPA Science Inventory

The resistance of bacteria to antimicrobial agents could be influenced by growth environment. The susceptibility of two enteric bacteria, Yersinia enterocolitica and Klebsiella pneumoniae, to chlorine dioxide was investigated. These organisms were grown in a defined medium in a c...

85

Microbiological investigation of Raphanus sativus L. grown hydroponically in nutrient solutions contaminated with spoilage and pathogenic bacteria.  

PubMed

The survival of eight undesired (spoilage/pathogenic) food related bacteria (Citrobacter freundii PSS60, Enterobacter spp. PSS11, Escherichia coli PSS2, Klebsiella oxytoca PSS82, Serratia grimesii PSS72, Pseudomonas putida PSS21, Stenotrophomonas maltophilia PSS52 and Listeria monocytogenes ATCC 19114(T)) was investigated in mineral nutrient solution (MNS) during the crop cycle of radishes (Raphanus sativus L.) cultivated in hydroponics in a greenhouse. MNSs were microbiologically analyzed weekly by plate count. The evolution of the pure cultures was also evaluated in sterile MNS in test tubes. The inoculated trials contained an initial total mesophilic count (TMC) ranging between 6.69 and 7.78Log CFU/mL, while non-sterile and sterile control trials showed levels of 4.39 and 0.97Log CFU/mL, respectively. In general, all inoculated trials showed similar levels of TMC in MNS during the experimentation, even though the levels of the inoculated bacteria decreased. The presence of the inoculums was ascertained by randomly amplified polymorphic DNA (RAPD) analysis applied on the isolates collected at 7-day intervals. At harvest, MNSs were also analyzed by denaturing gradient gel electrophoresis (DGGE). The last analysis, except P. putida PSS21 in the corresponding trial, did not detect the other bacteria, but confirmed that pseudomonads were present in un-inoculated MNSs. Despite the high counts detected (6.44 and 7.24CFU/g), only C. freundii PSS60, Enterobacter spp. PSS11 and K. oxytoca PSS82 were detected in radishes in a living form, suggesting their internalization. PMID:23290244

Settanni, Luca; Miceli, Alessandro; Francesca, Nicola; Cruciata, Margherita; Moschetti, Giancarlo

2013-01-01

86

The distribution of enteric bacteria from Australian mammals: host and geographical effects.  

PubMed

Bacteria of the family Enterobacteriaceae were isolated from 642 mammalian hosts, representing 16 families and 79 species, collected from throughout Australia. Escherichia coli was the most common of the 24 enteric species recovered and represented almost half of the isolates. Association analysis revealed that most other species of bacteria were less likely to be recovered from hosts in which E. coli was present. The composition of the enteric community of a host was found to be determined by both the taxonomic family to which the host belonged and the geographical area from which the host was collected. Hosts collected from the northern areas of Queensland and the Northern Territory had more diverse enteric communities than hosts collected from New South Wales or Western Australia. Hosts of the families Petauridae and Vespertilionidae had more diverse enteric communities than did members of the Macropodidae or Phalangeridae. The probability of occurrence of Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Hafnia alvei, Klebsiella oxytoca and K. pneumoniae in a host was found to vary with respect to host family and/or host locality. The non-random distribution of these species demonstrates the presence of extensive population structure and may suggest the existence of adaptations specific to both the primary and secondary habitats of these enteric bacteria. PMID:10537188

Gordon, D M; FitzGibbon, F

1999-10-01

87

Photoactivated ethidium monoazide directly cleaves bacterial DNA and is applied to PCR for discrimination of live and dead bacteria.  

PubMed

Ethidium monoazide (EMA) is a DNA intercalating agent and a eukaryotic topoisomerase II poison. We found that EMA treatment and subsequent visible light irradiation (photoactivation or photolysis) shows a bactericidal effect, hence the mechanism was analyzed. When bacterial cells were treated with more than 10 microg/ml of EMA for 1 hr plus photoactivation for 20 min, cleavage of bacterial DNA was confirmed by agarose gel electrophoresis and electron microscopic studies. The cleavage of chromosomal DNA was seen when it was treated in vitro with EMA and photolysis, which showed that the cleavage directly took place without the assistance of DNA gyrase/topoisomerase IV and the DNA repair enzymes of bacteria. It was also verified, by using negatively supercoiled pBR322 DNA, that medium/high concentrations of EMA (1 to 100 microg/ml) led to breaks of double-stranded DNA and that low concentrations of EMA (10 to 100 ng/ml) generated a single-stranded break. EMA is known to easily penetrate dead but not live bacteria. After treatment of 10 microg/ml of EMA for 30 min and photoactivation for 5 min, EMA cleaved the DNA of dead but not live Klebsiella oxytoca. When the cleaved DNA was used for templates in PCR targeting 16S rDNA, PCR product from the dead bacteria was completely suppressed. We demonstrated that EMA and photolysis directly cleaved bacterial DNA and are effective tools for discriminating live from dead bacteria by PCR. PMID:17704639

Soejima, Takashi; Iida, Ken-ichiro; Qin, Tian; Taniai, Hiroaki; Seki, Masanori; Takade, Akemi; Yoshida, Shin-ichi

2007-01-01

88

Nickel-resistant bacteria from anthropogenically nickel-polluted and naturally nickel-percolated ecosystems.  

PubMed

DNA fragments harboring the nickel resistance determinants from bacteria isolated from anthropogenically polluted ecosystems in Europe and Zaire were compared with those harboring the nickel resistance determinants from bacteria isolated from naturally nickel-percolated soils from New Caledonia by DNA-DNA hybridization. The biotinylated DNA probes were derived from the previously described Alcaligenes eutrophus CH34, Alcaligenes xylosoxidans 31A, Alcaligenes denitrificans 4a-2, and Klebsiella oxytoca CCUG 15788 and four new nickel resistance-determining fragments cloned from strains isolated from soils under nickel-hyperaccumulating trees. Nine probes were hybridized with endonuclease-cleaved plasmid and total DNA samples from 56 nickel-resistant strains. Some of the New Caledonian strains were tentatively identified as Acinetobacter, Pseudomonas mendocina, Comamonas, Hafnia alvei, Burkholderia, Arthrobacter aurescens, and Arthrobacter ramosus strains. The DNA of most strains showed homologies to one or several of the following nickel resistance determinants: the cnr and ncc operons of the strains A. eutrophus CH34 and A. xylosoxidans 31A, respectively, the nre operon of strain 31A, and the nickel resistance determinants of K. oxytoca. On the basis of their hybridization reactions the nickel resistance determinants of the strains could be assigned to four groups: (i) cnr/ncc type, (ii) cnr/ncc/nre type, (iii) K. oxytoca type, and (iv) others. The majority of the strains were assigned to the known groups. Among the strains from Belgium and Zaire, exclusively the cnr/ncc and the cnr/ncc/nre types were found. Among the New Caledonian strains all four types were represented. Homologies to the nre operon were found only in combination with the cnr/ncc operon. The homologies to the cnr/ncc operon were the most abundant and were detected alone or together with homologies to the nre operon. Only the DNA of the strains isolated from soil in Scotland and the United States and that of five of the New Caledonian strains did not show any detectable homologies to any of our probes. The nickel resistance fragment isolated from Burkholderia strain 32W-2 was studied in some detail. This 15-kb BamHI fragment conferred resistance to 1 to 5 mM NiCl(inf2) to Escherichia coli and resistance to up to 25 mM NiCl(inf2) to A. eutrophus. It showed strong homologies to both the cnr/ncc operon and the nre operon and conferred strictly regulated (inducible) nickel resistance to A. eutrophus. PMID:16535048

Stoppel, R; Schlegel, H G

1995-06-01

89

Susceptibility to levofloxacin of clinical isolates of bacteria from intensive care and haematology/oncology patients in Switzerland: a multicentre study.  

PubMed

The objective of this study was to examine the susceptibility of clinical isolates to levofloxacin, a fluoroquinolone with extended activity against Gram-positive bacteria, and other antibiotics in 12 Swiss clinical microbiology laboratories using the NCCLS disc diffusion technique. Isolates were prospectively collected from intensive care units (ICUs (59%), oncology wards (7%) and other units with haematology/oncology patients (34%) from June 1995 to March 1996. The levofloxacin breakpoints used were as recommended by the manufacturer. A total of 310 Gram-positive and 580 Gram-negative isolates from the respiratory tract (36%), skin/wounds (12%), blood (16%), urine (17%) and other sources (19%) were tested. The percentage of isolates susceptible to levofloxacin was 100% for Enterococcus spp. (38 strains), Streptococcus agalactiae (13), Streptococcus pneumoniae (65), Acinetobacter spp. (11), Citrobacter diversus (6), Citrobacter freundii (17), Klebsiella oxytoca (39), Morganella morganii (16), Proteus mirabilis (20), Proteus vulgaris (23), Serratia spp. (19), Stenotrophomonas maltophilia (10) and Haemophilus influenzae (41). The percentage of isolates susceptible to levofloxacin for Staphylococcus aureus (95 strains, including 2% MRSA) was 94%, coagulase-negative staphylococci (85) 65%, Enterobacter spp. (75) 99%, Escherichia coli (111) 97%, Klebsiella pneumoniae (45) 98% and Pseudomonas aeruginosa (124) 87%. In conclusion, levofloxacin is a new fluoroquinolone to which the most common clinical isolates in Switzerland are susceptible. The susceptibility of Enterococcus spp. and S. pneumoniae to levofloxacin was particularly remarkable. This compound appears to be a promising therapeutic alternative for the treatment of Gram-positive infections. PMID:10404338

Siegrist, H H; Nepa, M C; Jacquet, A

1999-06-01

90

Enhanced activity of meso-secondary alcohol dehydrogenase from Klebsiella species by codon optimization.  

PubMed

Meso-secondary alcohol dehydrogenases (meso-SADH) from Klebsiella oxytoca KCTC1686 and Klebsiella pneumoniae KCTC2242 were codon optimized and expressed in Escherichia coli W3110. The published gene data of K. pneumoniae NTUH-K2044 (NCBI accession number AP006725), K. pneumoniae 342 (NCBI accession number CP000964), and K. pneumoniae MGH 78578 (NCBI accession number CP000647), were compared with the meso-SADH sequences of each strain, respectively. Codon-optimized meso-SADH enzymes of K. oxytoca and K. pneumoniae showed approximately twofold to fivefold increased enzyme activities for acetoin reduction over native enzymes. The highest activities for each strain were obtained at 30-37 °C and pH 6-7 (yielding 203.1 U/mg of protein and 156.5 U/mg of protein, respectively). The increased enzyme activity of the codon-optimized enzymes indicated that these modified enzymes could convert acetoin into 2,3-butanediol with a high yield. PMID:23053416

Lee, Soojin; Kim, Borim; Oh, Minkyu; Kim, Youngrok; Lee, Jinwon

2013-07-01

91

Evaluation of the MicroScan ESBL plus confirmation panel for detection of extended-spectrum b-lactamases in clinical isolates of oxyimino-cephalosporin-resistant Gram-negative bacteria  

Microsoft Academic Search

Objective: We aimed to assess the performance of the MicroScan ESBL plus confirmation panel using a series of 87 oxyimino-cephalosporin-resistant Gram-negative bacilli of various species. Methods: Organisms tested included 57 extended-spectrum b-lactamase (ESBL) strains comprising Enterobacter aerogenes (3), Enterobacter cloacae (10), Escherichia coli (11), Klebsiella pneumoniae (26), Klebsiella oxytoca (3) and Proteus mirabilis (4). Also included were 30 strains resistant

Enno Sturenburg; Melanie Lang; Matthias A. Horstkotte; Rainer Laufs; Dietrich Mack

2004-01-01

92

Klebsiella pneumoniae Flocculation Dynamics  

PubMed Central

The bacterial pathogen Klebsiella pneumoniae is a cause of community- and hospital-acquired lung, urinary tract, and blood stream infections. A common contaminant of indwelling catheters, it is theorized that a common infection pathway for this organism is via shedding of aggregates off of biofilm colonies. In an effort to better understand bacterial proliferation in the host bloodstream, we develop a PDE model for the flocculation dynamics of Klebsiella pneumoniae in suspension. Existence and uniqueness results are provided, as well as a brief description of the numerical approximation scheme. We generate artificial data and illustrate the requirements to accurately identify proliferation, aggregation, and fragmentation of flocs in the experimental domain of interest.

Jackson, T. L.; Taylor, K. A.; Thompson, A. P.; Younger, J. G.

2011-01-01

93

Isolation and characterization of multidrug-resistant Klebsiella spp. isolated from shrimp imported from Thailand.  

PubMed

A study was undertaken to isolate and characterize tetracycline and nalidixic acid-resistant Klebsiella spp. in farm-raised, imported shrimp sold in the United States. Sixty-seven multiple antibiotic-resistant Klebsiella spp. strains were isolated from imported shrimp samples. Using morphological and biochemical methods, fifty-three strains were tentatively identified as Klebsiella pneumoniae and fourteen as K. oxytoca. Although all isolates were resistant to tetracycline, only 8 were resistant to nalidixic acid. These 8 isolates were further screened by PCR for quinolone resistance genes (qnrA, B, S, gyrA, B and parC). PCR protocols failed to amplify any qnr genes. The purified PCR amplicons of gyrA, gyrB and parC were sequenced and analyzed for point mutations that confer resistance to fluoroquinolone antibiotics. Analysis of the sequences of the gyrA amplicons from nalidixic acid-resistant Klebsiella spp. indicated two point mutations in gyrA at positions 83 (Ser?Phe) and 87 (Asp?Ala). Sequence analysis of the parC amplicons indicated an amino acid change at position 80 (Ser?Ile). No mutations were detected in gyrB. Template DNA from all isolates was screened for tetracycline resistance genes (tetA-E). Oligonucleotide primers specifically targeting a 305-bp region of tetB and a 477-bp region of tetD successfully amplified sequences from 91.0 and 44.0% of the isolates, respectively. None of the isolates contained tetA, tetC or tetE genes. Plasmids (2.0-16.0kb) were found in 23 of the 67 isolates. XbaI-PFGE identified 32 distinct macro restriction patterns (mrps) among the 61 multiple drug-resistant Klebsiella spp. that were typable. Our results indicate that imported shrimp is a reservoir for multidrug resistant Klebsiella spp. and potential health risks posed by such strains should not be underestimated. PMID:22405354

Nawaz, Mohamed; Khan, S A; Tran, Q; Sung, K; Khan, A A; Adamu, I; Steele, R S

2012-04-16

94

Kinetics of Colonization of Adult Queensland Fruit Flies (Bactrocera tryoni) by Dinitrogen-Fixing Alimentary Tract Bacteria  

PubMed Central

The average total population of bacteria remained constant in the alimentary tracts of adult laboratory-raised Queensland fruit flies (Bactrocera tryoni) although the insects had ingested large numbers of live bacteria as part of their diet. The mean number of bacteria (about 13 million) present in the gut of the insects from 12 to 55 days after emergence was not significantly modified when, at 5 days after emergence, the flies were fed antibiotic-resistant bacteria belonging to two species commonly isolated from the gut of field-collected B. tryoni. Flies were fed one marked dinitrogen-fixing strain each of either Klebsiella oxytoca or Enterobacter cloacae, and the gastrointestinal tracts of fed flies were shown to be colonized within 7 days by antibiotic-resistant isolates of K. oxytoca but not E. cloacae. The composition of the microbial population also appeared to be stable in that the distribution and frequency of bacterial taxa among individual flies exhibited similar patterns whether or not the flies had been bacteria fed. Isolates of either E. cloacae or K. oxytoca, constituting 70% of the total numbers, were usually dominant, with oxidative species including pseudomonads forming the balance of the population. Antibiotic-resistant bacteria could be spread from one cage of flies to the adjacent surfaces of a second cage within a few days and had reached a control group several meters distant by 3 weeks. Restriction of marked bacteria to the population of one in five flies sampled from the control group over the next 30 days suggested that the bacterial population in the gut of the insect was susceptible to alteration in the first week after emergence but that thereafter it entered a steady state and was less likely to be perturbed by the introduction of newly encountered strains. All populations sampled, including controls, included at least one isolate of the dinitrogen-fixing family Enterobacteriaceae; many were distinct from the marked strains fed to the flies. Nitrogenase activity detected by the acetylene reduction assay was associated with flies fed dinitrogen-fixing bacteria as well as with control groups given either no supplement or free access to a yeast hydrolysate preparation. Nitrogen fixed from the atmosphere may supplement the nutrition of the alimentary tract microbial population of B. tryoni. Transmission electron microscopy showed that the principal site of bacterial colonization in the abdominal alimentary tract was the lumen of the midgut inside the peritrophic membrane. No intracellular symbionts were seen in the gut tissues nor were bacteria found attached to the cuticular folds of the hindgut. The ultrastructure of the gut resembled that of other fly genera except that the intercellular spaces between rectal epithelial cells were more extensive, suggesting a role for unspecialized epithelium in water and solute uptake in B. tryoni. Images

Murphy, Kathleen M.; Teakle, David S.; MacRae, Ian C.

1994-01-01

95

Prevalence of clinical isolates of Escherichia coli and Klebsiella spp. producing multiple extended-spectrum beta-lactamases.  

PubMed

Eleven thousand two hundred seventy-two Escherichia coli, 1109 Klebsiella pneumoniae, 1124 Salmonella enterica, and 602 Klebsiella oxytoca unrelated clinical isolates were obtained between 2001 and 2004 in a university hospital in Salamanca, Spain. One hundred thirteen E. coli (1%), 32 K. pneumoniae (2.9%), 4 K. oxytoca (0.66%), and 5 S. enterica (0.44%) isolates produced extended-spectrum beta-lactamases (ESBLs). We obtained 42.2% of the ESBL-producing isolates from outpatients and 57.8% from inpatients. The most commonly detected ESBLs were CTX-M 14 (43.5% of ESBL-producing isolates), TEM-116 (22.1%), and SHV-2 (15.6%). A CTX-M 27-producing E. coli is 1st reported in Spain in this study. Two (20 isolates, 13%) or 3 (7 isolates, 4.5%) ESBLs were produced by 17.5% of ESBL-producing isolates (27 isolates). The most frequent combinations were CTX-M 14 + TEM-116 (5.7%), SHV-12 + TEM-116 (2.6%), and SHV-2 + CTX-M 14 + TEM-116 (2.6%). Clonal diversity was high even between isolates producing the same combinations of 2 or 3 beta-lactamases. PMID:17913435

Romero, Emilio David Valverde; Padilla, Trinidad Parras; Hernández, Ana Herrero; Grande, Rosa Pérez; Vázquez, Marta Fernández; García, Inmaculada García; García-Rodríguez, José Angel; Muñoz Bellido, Juan Luis

2007-12-01

96

A Study of Biochemical Properties of Bacteria of the Hafnia Genus (Izuchenie Biokhimicheskikh Svoitv Bakterii Roda Hafnia).  

National Technical Information Service (NTIS)

The bacteria Hafnia belong to the family Enterobacteriaceae. According to the data of the Subcommittee on Enterobacteriaceae (1963) and Kauffmann (1966) the genus Hafnia is classified in the tribe Klebsiella along with the genuses Klebsiella, Enterobacter...

Y. Kizevalter

1973-01-01

97

Effect of Algae and Plant Lectins on Planktonic Growth and Biofilm Formation in Clinically Relevant Bacteria and Yeasts  

PubMed Central

This study aimed to evaluate the abilities of plant and algae lectins to inhibit planktonic growth and biofilm formation in bacteria and yeasts. Initially, ten lectins were tested on Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella oxytoca, Pseudomonas aeruginosa, Candida albicans, and C. tropicalis at concentrations of 31.25 to 250??g/mL. The lectins from Cratylia floribunda (CFL), Vatairea macrocarpa (VML), Bauhinia bauhinioides (BBL), Bryothamnion seaforthii (BSL), and Hypnea musciformis (HML) showed activities against at least one microorganism. Biofilm formation in the presence of the lectins was also evaluated; after 24?h of incubation with the lectins, the biofilms were analyzed by quantifying the biomass (by crystal violet staining) and by enumerating the viable cells (colony-forming units). The lectins reduced the biofilm biomass and/or the number of viable cells to differing degrees depending on the microorganism tested, demonstrating the different characteristics of the lectins. These findings indicate that the lectins tested in this study may be natural alternative antimicrobial agents; however, further studies are required to better elucidate the functional use of these proteins.

Vasconcelos, Mayron Alves; Arruda, Francisco Vassiliepe Sousa; Carneiro, Victor Alves; Silva, Helton Colares; Nascimento, Kyria Santiago; Sampaio, Alexandre Holanda; Cavada, Benildo; Teixeira, Edson Holanda; Henriques, Mariana

2014-01-01

98

Extended-spectrum ?-lactamases in Gram Negative Bacteria  

PubMed Central

Extended-spectrum ?-lactamases (ESBLs) are a group of plasmid-mediated, diverse, complex and rapidly evolving enzymes that are posing a major therapeutic challenge today in the treatment of hospitalized and community-based patients. Infections due to ESBL producers range from uncomplicated urinary tract infections to life-threatening sepsis. Derived from the older TEM is derived from Temoniera, a patient from whom the strain was first isolated in Greece. ?-lactamases, these enzymes share the ability to hydrolyze third-generation cephalosporins and aztreonam and yet are inhibited by clavulanic acid. In addition, ESBL-producing organisms exhibit co-resistance to many other classes of antibiotics, resulting in limitation of therapeutic option. Because of inoculum effect and substrate specificity, their detection is also a major challenge. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in Klebsiella pneumoniae, K. oxytoca, Escherichia coli and Proteus mirabilis. In common to all ESBL-detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic-resistance mechanisms in the face of the introduction of new antimicrobial agents. Thus there is need for efficient infection-control practices for containment of outbreaks; and intervention strategies, e.g., antibiotic rotation to reduce further selection and spread of these increasingly resistant pathogens.

Rawat, Deepti; Nair, Deepthi

2010-01-01

99

Duodenal-mucosal bacteria associated with celiac disease in children.  

PubMed

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of cereal gluten proteins. This disorder is associated with imbalances in the gut microbiota composition that could be involved in the pathogenesis of CD. The aim of this study was to characterize the composition and diversity of the cultivable duodenal mucosa-associated bacteria of CD patients and control children. Duodenal biopsy specimens from patients with active disease on a gluten-containing diet (n = 32), patients with nonactive disease after adherence to a gluten-free diet (n = 17), and controls (n = 8) were homogenized and plated on plate count agar, Wilkins-Chalgren agar, brain heart agar, or yeast, Casitone, and fatty acid agar. The isolates were identified by partial 16S rRNA gene sequencing. Renyi diversity profiles showed the highest diversity values for active CD patients, followed by nonactive CD patients and control individuals. Members of the phylum Proteobacteria were more abundant in patients with active CD than in the other child groups, while those of the phylum Firmicutes were less abundant. Members of the families Enterobacteriaceae and Staphylococcaceae, particularly the species Klebsiella oxytoca, Staphylococcus epidermidis, and Staphylococcus pasteuri, were more abundant in patients with active disease than in controls. In contrast, members of the family Streptococcaceae were less abundant in patients with active CD than in controls. Furthermore, isolates of the Streptococcus anginosus and Streptococcus mutans groups were more abundant in controls than in both CD patient groups, regardless of inflammatory status. The findings indicated that the disease is associated with the overgrowth of possible pathobionts that exclude symbionts or commensals that are characteristic of the healthy small intestinal microbiota. PMID:23835180

Sánchez, Ester; Donat, Ester; Ribes-Koninckx, Carmen; Fernández-Murga, Maria Leonor; Sanz, Yolanda

2013-09-01

100

Duodenal-Mucosal Bacteria Associated with Celiac Disease in Children  

PubMed Central

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of cereal gluten proteins. This disorder is associated with imbalances in the gut microbiota composition that could be involved in the pathogenesis of CD. The aim of this study was to characterize the composition and diversity of the cultivable duodenal mucosa-associated bacteria of CD patients and control children. Duodenal biopsy specimens from patients with active disease on a gluten-containing diet (n = 32), patients with nonactive disease after adherence to a gluten-free diet (n = 17), and controls (n = 8) were homogenized and plated on plate count agar, Wilkins-Chalgren agar, brain heart agar, or yeast, Casitone, and fatty acid agar. The isolates were identified by partial 16S rRNA gene sequencing. Renyi diversity profiles showed the highest diversity values for active CD patients, followed by nonactive CD patients and control individuals. Members of the phylum Proteobacteria were more abundant in patients with active CD than in the other child groups, while those of the phylum Firmicutes were less abundant. Members of the families Enterobacteriaceae and Staphylococcaceae, particularly the species Klebsiella oxytoca, Staphylococcus epidermidis, and Staphylococcus pasteuri, were more abundant in patients with active disease than in controls. In contrast, members of the family Streptococcaceae were less abundant in patients with active CD than in controls. Furthermore, isolates of the Streptococcus anginosus and Streptococcus mutans groups were more abundant in controls than in both CD patient groups, regardless of inflammatory status. The findings indicated that the disease is associated with the overgrowth of possible pathobionts that exclude symbionts or commensals that are characteristic of the healthy small intestinal microbiota.

Sanchez, Ester; Donat, Ester; Ribes-Koninckx, Carmen; Fernandez-Murga, Maria Leonor

2013-01-01

101

EPIDEMIOLOGICAL STUDY OF 'KLEBSIELLA PNEUMONIAE' AMONG PULP AND PAPER MILL WORKERS  

EPA Science Inventory

This one-year study measured fecal coliform and Klebsiella bacteria densities in several of Wisconsin's pulp and paper mill processing wash waters, treated waters, and waters receiving pulp and paper mill effluent discharge. The isolation of fecal coliform bacteria ranged from as...

102

Genotoxic Klebsiella pneumoniae in Taiwan  

PubMed Central

Background Colibactin is a nonribosomal peptide-polyketide synthesized by multi-enzyme complexes encoded by the pks gene cluster. Colibactin-producing Escherichia coli have been demonstrated to induce host DNA damage and promote colorectal cancer (CRC) development. In Taiwan, the occurrence of pyogenic liver abscess (PLA) has been suggested to correlate with an increasing risk of CRC, and Klebsiella pneumoniae is the predominant PLA pathogen in Taiwan Methodology/Principal Findings At the asn tRNA loci of the newly sequenced K. pneumoniae 1084 genome, we identified a 208-kb genomic island, KPHPI208, of which a module identical to the E. coli pks colibactin gene cluster was recognized. KPHPI208 consists of eight modules, including the colibactin module and the modules predicted to be involved in integration, conjugation, yersiniabactin production, microcin production, and unknown functions. Transient infection of BALB/c normal liver cells with K. pneumoniae 1084 increased the phosphorylation of histone H2AX, indicating the induction of host DNA damage. Colibactin was required for the genotoxicity of K. pneumoniae 1084, as it was diminished by deletion of clbA gene and restored to the wild type level by trans-complementation with a clbA coding plasmid. Besides, BALB/c mice infected with K. pneumoniae 1084 exhibited enhanced DNA damage in the liver parenchymal cells when compared to the isogenic clbA deletion mutant. By PCR detection, the prevalence of pks-positive K. pneumoniae in Taiwan is 25.6%, which is higher than that reported in Europe (3.5%), and is significantly correlated with K1 type, which predominantly accounted for PLA in Taiwan. Conclusions Our knowledge regarding how bacteria contribute to carcinogenesis has just begun. The identification of genotoxic K. pneumoniae and its genetic components will facilitate future studies to elucidate the molecular basis underlying the link between K. pneumoniae, PLA, and CRC.

Lai, Yi-Chyi; Lin, Ann-Chi; Chiang, Ming-Ko; Dai, Yu-Han; Hsu, Chih-Chieh; Lu, Min-Chi; Liau, Chun-Yi; Chen, Ying-Tsong

2014-01-01

103

Screening and characterization of bioflocculant produced by isolated Klebsiella sp  

Microsoft Academic Search

Sixteen strains of polymer-producing bacteria were isolated from the activated sludge samples taken from two seafood processing\\u000a plants in Southern Thailand. Their culture broths possessed the ability to flocculate kaolin suspension in the presence of\\u000a 1% CaCl2. Based on the flocculating activity, the strain S11 was selected and identified to be a Klebsiella sp. using the partial 16S rRNA sequencing

W. Dermlim; P. Prasertsan; H. Doelle

1999-01-01

104

Characterization and identification of virulent Klebsiella oxytoca isolated from abalone ( Haliotis diversicolor supertexta) postlarvae with mass mortality in Fujian, China  

Microsoft Academic Search

An epidemic of mass mortality of abalone (Haliotis diversicolor supertexta) postlarvae aged 40 days or less has existed across south coast of China since the second half of 2002. Among 20 bacterial strains isolated from diseased abalone postlarvae on 2216E marine agar plates during an outbreak of postlarval disease in August 2005, a predominant strain (designated strain 20) was demonstrated

Junpeng Cai; Zexiu Wang; Chuanhua Cai; Yiping Zhou

2008-01-01

105

Enantioselective oxidation of amphetamine by copper-containing quinoprotein amine oxidases from Escherichia coli and Klebsiella oxytoca  

Microsoft Academic Search

The enantioselective properties of copper-containing quinoprotein amine oxidase (EC 1.4.3.6) from Escherichiacoli K12 and Klebsiellaoxytoca in the kinetic resolution of (R,S)-1-phenyl-2-aminopropane, amphetamine, have been determined. Determination of the enantiomeric ratio, E=(kcat\\/KM)R\\/(kcat\\/KM)S, the ratio of specificity constants for the enantiomeric substrates, can be accomplished in several ways. For practical reasons, we calculated E using non-linear regression analysis of initial rate data

Ayse Hacisalihoglu; Aldo Jongejan; Jaap A Jongejan; Johannis A Duine

2000-01-01

106

Studies on water quality and pathogenic bacteria in coastal water Langkawi, Malaysia.  

PubMed

A study on physico-chemical parameters and pathogenic bacterial community was carried out at the coastal waters of Pulau Tuba island, Langkawi. The physico-chemical parameters such as temperature (27.43-28.88 degrees C), dissolved oxygen (3.79-6.49 mg l(-1)), pH (7.72-8.20), salinity (33.10-33.96 ppt), total dissolved solids (32.27-32.77 g l(-1)) and specific conductivity (49.83-51.63 mS cm(-1)) were observed. Station 3 and station 4 showed highest amount of nitrates (26.93 and 14.61 microg at N l(-1)) than station 1 (2.04 microg at N l(-1)) and station 2 (4.18 microg at N l(-1)). The highest concentration (12.4 +/- microg l(-1)) of chlorophyll a was observed in station 4 in October 2005. High phosphorus content (561 microg P l(-1)) was found in the station 2. Thirteen bacterial isolates were successfully identified using API 20E system. The highest amount of bacteria was observed at Station 4 (3400 CFU ml(-1)) and the lowest numberwas at Station 2 (890 CFU ml(-1)). Out of identified 13 Gram-negative bacterial isolates dominant species were Aeromonas hydrophila, Klebsiella oxytoca, Pseudomonas baumannii, Vibrio vulnificus, Proteus mirabilis, Providencia alcalifaciens and Serratia liquefaciens. Apart from this, oil biodegrading Pseudomonas putida were also identified. The study reveals the existing status of water quality is still conducive and the reasonably diverse with Gram-negative bacteria along the Pulau Tuba Langkawi. PMID:23360015

Jalal, K C A; Faizul, H N Noor; Naim, M Azrul; John, B Akbar; Kamaruzzaman, B Y

2012-07-01

107

Removal of pathogenic factors from 2,3-butanediol-producing Klebsiella species by inactivating virulence-related wabG gene.  

PubMed

Klebsiella species are the most extensively studied among a number of 2,3-butanediol (2,3-BDO)-producing microorganisms. The ability to metabolize a wide variety of substrates together with the ease of cultivation made this microorganisms particularly promising for the application in industrial-scale production of 2,3-BDO. However, the pathogenic characteristics of encapsulated Klebsiella species are considered to be an obstacle hindering their industrial applications. Here, we removed the virulence factors from three 2,3-BDO-producing strains, Klebsiella pneumoniae KCTC 2242, Klebsiella oxytoca KCTC1686, and K. oxytoca ATCC 43863 through site-specific recombination technique. We generated deletion mutation in wabG gene encoding glucosyltransferase which plays a key role in the synthesis of outer core lipopolysaccharides (LPS) by attaching the first outer core residue D-GalAp to the O-3 position of the L,D-HeppII residue. The morphologies and adhesion properties against epithelial cells were investigated, and the results indicated that the wabG mutant strains were devoid of the outer core LPS and lost the ability to retain capsular structure. The time profile of growth and 2,3-BDO production from K. pneumoniae KCTC 2242 and K. pneumoniae KCTC 2242 ?wabG were analyzed in batch culture with initial glucose concentration of 70 g/l. The growth was not affected by disrupting wabG gene, but the production of 2,3-BDO decreased from 31.27 to 22.44 g/l in mutant compared with that of parental strain. However, the productions of acetoin and lactate from wabG mutant strain were negligible, whereas that from parental strain reached to ~5 g/l. PMID:22832986

Jung, Sung-Geun; Jang, Jun-Ho; Kim, Ah-Young; Lim, Min-Cheol; Kim, Borim; Lee, Jinwon; Kim, Young-Rok

2013-03-01

108

Hypervirulent (hypermucoviscous) Klebsiella pneumoniae  

PubMed Central

A new hypervirulent (hypermucoviscous) variant of Klebsiella pneumoniae has emerged. First described in the Asian Pacific Rim, it now increasingly recognized in Western countries. Defining clinical features are the ability to cause serious, life-threatening community-acquired infection in younger healthy hosts, including liver abscess, pneumonia, meningitis and endophthalmitis and the ability to metastatically spread, an unusual feature for enteric Gram-negative bacilli in the non-immunocompromised. Despite infecting a healthier population, significant morbidity and mortality occurs. Although epidemiologic features are still being defined, colonization, particularly intestinal colonization, appears to be a critical step leading to infection. However the route of entry remains unclear. The majority of cases described to date are in Asians, raising the issue of a genetic predisposition vs. geospecific strain acquisition. The traits that enhance its virulence when compared with “classical” K. pneumoniae are the ability to more efficiently acquire iron and perhaps an increase in capsule production, which confers the hypermucoviscous phenotype. An objective diagnostic test suitable for routine use in the clinical microbiology laboratory is needed. If/when these strains become increasingly resistant to antimicrobials, we will be faced with a frightening clinical scenario.

Shon, Alyssa S.; Bajwa, Rajinder P.S.; Russo, Thomas A.

2013-01-01

109

Population dynamics of bacteria associated with different strains of the pine wood nematode Bursaphelenchus xylophilus after inoculation in maritime pine (Pinus pinaster).  

PubMed

For a long time it was thought that Bursaphelenchus xylophilus was the only agent of the pine wilt disease. Recently, it was discovered that there are bacteria associated with the nematodes that contribute to the pathogenesis of this disease, mainly through the release of toxins that promote the death of the pines. Among the species most commonly found, are bacteria belonging to the Bacillus, Pantoea, Pseudomonas and Xanthomonas genera. The main objective of this work was to study the effect of inoculation of maritime pine (Pinus pinaster) with four different nematode isolates, in the bacterial population of nematodes and trees, at different stages of disease progression. The monitoring of progression of disease symptoms was also recorded. Also, the identification of bacteria isolated from the xylem of trees and the surface of nematodes was performed by classical identification methods, by the API20E identification system and by sequencing of bacterial DNA. The results showed that for the symptoms progression, the most striking difference was observed for the pines inoculated with the avirulent isolate, C14-5, which led to a slower and less severe aggravation of symptoms than in pines inoculated with the virulent isolates. In general, it was found that bacterial population, inside the tree, increased with disease progression. A superior bacterial quantity was isolated from pines inoculated with the nematode isolates HF and 20, and, comparatively, few bacteria were isolated from pines inoculated with the avirulent isolate. The identification system API20E was insufficient in the identification of bacterial species; Enterobacter cloacae species was identified in 79% of the isolated bacterial colonies and seven of these colonies could not be identified by this method. Molecular identification methods, through bacterial DNA sequencing, allowed a more reliable identification: eleven different bacterial species within the Bacillus, Citrobacter, Enterobacter, Escherichia, Klebsiella, Paenibacillus, Pantoea and Terribacillus genera were identified. General bacterial diversity increased with the progression of the disease. Bacillus spp. were predominant at the earlier stage of disease progression and Klebsiella oxytoca at the later stages. Furthermore, bacterial species isolated from the surface of nematodes were similar to those isolated from the xylem of pines. In the present work new bacterial species were identified which have never been reported before in this type of study and may be associated with their geographical origin (Portugal). P. pinaster, the pine species used in this study, was different from those commonly grown in Japan and China. Furthermore, it was the first time that bacteria were isolated and identified from an avirulent pine wood nematode isolate. PMID:21570967

Roriz, Mariana; Santos, Carla; Vasconcelos, Marta W

2011-08-01

110

Prevalence and Antimicrobial Susceptibility Patterns of Bacteria from Milkmen and Cows with Clinical Mastitis in and around Kampala, Uganda  

PubMed Central

Background Identification of pathogens associated with bovine mastitis is helpful in treatment and management decisions. However, such data from sub-Saharan Africa is scarce. Here we describe the distribution and antimicrobial susceptibility patterns of bacteria from cows with clinical mastitis in Kampala, Uganda. Due to high concern of zoonotic infections, isolates from milkmen are also described. Methodology/Principal Findings Ninety seven milk samples from cows with clinical mastitis and 31 nasal swabs from milkmen were collected (one sample per cow/human). Fifty eight (60%) Gram-positive isolates namely Staphylococci (21), Enterococci (16), Streptococci (13), Lactococci (5), Micrococci (2) and Arcanobacteria (1) were detected in cows; only one grew Staphylococcus aureus. Furthermore, 24 (25%) coliforms namely Escherichia coli (12), Klebsiella oxytoca (5), Proteus vulgaris (2), Serratia (2), Citrobacter (1), Cedecea (1) and Leclercia (1) were identified. From humans, 24 Gram-positive bacteria grew, of which 11 were Staphylococci (35%) including four Staphylococcus aureus. Upon susceptibility testing, methicillin-resistant coagulase-negative staphylococci (CoNS) were prevalent; 57%, 12/21 in cows and 64%, 7/11 in humans. However, methicillin-resistant Staphylococcus aureus was not detected. Furthermore, methicillin and vancomycin resistant CoNS were detected in cows (Staphylococcus hominis, Staphylococcus lugdunensis) and humans (Staphylococcus scuiri). Also, vancomycin and daptomycin resistant Enterococci (Enterococcus faecalis and Enterococcus faecium, respectively) were detected in cows. Coliforms were less resistant with three pan-susceptible isolates. However, multidrug resistant Klebsiella, Proteus, Serratia, Cedecea, and Citrobacter were detected. Lastly, similar species grew from human and bovine samples but on genotyping, the isolates were found to be different. Interestingly, human and bovine Staphylococcus aureus were genetically similar (spa-CC435, spa-type t645 corresponding to ST121) but with different susceptibility patterns. Conclusions/Significance CoNS, Enterococci, Streptococci, and Escherichia coli are the predominant pathogens associated with clinical bovine-mastitis in Kampala, Uganda. Multidrug resistant bacteria are also prevalent. While similar species occurred in humans and cows, transmission was not detected.

Kateete, David Patrick; Kabugo, Usuf; Baluku, Hannington; Nyakarahuka, Luke; Kyobe, Samuel; Okee, Moses; Najjuka, Christine Florence; Joloba, Moses Lutaakome

2013-01-01

111

Draft Genome Sequence of NDM-1-Producing Klebsiella pneumoniae Clinical Isolate 303K  

PubMed Central

Multidrug-resistant New Delhi metallo-?-lactamase 1 (NDM-1)-producing bacteria have spread globally and become a major clinical and public health threat. We report here the draft genome sequence of the Klebsiella pneumoniae clinical isolate 303K, harboring an NDM-1 coding sequence.

Liao, Yu-Chieh; Chen, Ying-Hsiang; Lin, Hsin-Hung; Mu, Jung-Jung; Wu, Ho-Sheng

2013-01-01

112

Interaction of Klebsiella capsule type 7 with human polymorphonuclear leucocytes.  

PubMed

Klebsiella serotype K7 is found among the capsule types that are most prevalent in respiratory tract isolates. To evaluate the significance of the K7 antigen in bacteria-leucocyte interactions, K7-encapsulated Klebsiella pneumoniae strains and their non-capsulate mutants were investigated. The K7 isolates were compared to K2-capsulate strains and their respective K- derivatives. K7-capsulate bacteria were less hydrophilic, and more readily phagocytosed and killed by human polymorphonuclear leucocytes (PMNL) than K2 strains. Loss of the K7 antigen resulted in increased surface hydrophobicity but did not affect phagocytosis and killing, whereas loss of the K2 capsule caused greater susceptibility to the phagocytic and killing action of PMNL. Both the K7 and K2 antigen stimulated the extracellular release of lysozyme from neutrophils but not of myeloperoxidase, indicating degranulation of only secondary granules. All K- mutants induced the release of both lysozyme and myeloperoxidase. Our results suggest that, in contrast to the K2 antigen, the K7 capsular polysaccharide does not confer antiphagocytic properties on bacteria. However, the K7 antigen is able to impede the extracellular release of primary granule enzymes. PMID:1338474

Podschun, R; Penner, I; Ullmann, U

1992-11-01

113

The capsular polysaccharide of Klebsiella serotype K60; a novel, structural pattern.  

PubMed

Non-linear capsular polysaccharides of Klebsiella bacteria usually have a single side-chain per repeating unit, or, less commonly, two side-chains attached to the same unit. The capsular polysaccharide from Klebsiella serotype K60 is unique in having three side-chains in the heptasaccharide repeating-unit shown. The structure, including the configuration of the glycosidic linkages, was established mainly by characterization of the oligosaccharides obtained by partial hydrolysis of both the original, capsular polysaccharide and the polymer resulting from the removal, by Smith degradation, of the side chains (Formula, see text). PMID:7438138

Dutton, G G; Di Fabio, J

1980-12-01

114

Acute suppurative klebsiella thyroiditis: a case report.  

PubMed

Acute suppurative thyroiditis and thyroid abscess are extremely rare disorders. The most common pathogens causing acute suppurative thyroiditis are Gram-positive bacteria, including staphylococcal and streptococcal species. Thyroid abscess is mostly located in the left thyroid lobe. We report the case of a 75-year-old female patient with acute suppurative thyroiditis and right lobe thyroid abscess caused by Klebsiella spp. The patient had a firm, livid, hardly mobile cervical swelling. Axial computed tomography image showed soft-tissue swelling, an abscess in the right thyroid lobe and swelling of the thyroid gland. The diagnosis was established on a smear culture result. The patient was diabetic and had been operated on for goitre fifty years before. On indirect laryngoscopic examination, the patient was found to have right vocal cord paralysis. Infection and abscess resolved following surgical drainage and treatment with intravenous antibiotics, while the vocal cord paralysis persisted. Diabetes mellitus and previous thyroid surgery, in which sutures were used with unresorptive material, might have been the precipitating factors for the patient to acquire this unusual infection. PMID:19499695

Bukvic, B; Diklic, A; Zivaljevic, V

2009-01-01

115

Influence of Cefodizime on Pulmonary Inflammatory Response to Heat-Killed Klebsiella pneumoniae in Mice  

PubMed Central

Encapsulated Klebsiella pneumoniae strains frequently induce fatal nosocomial pneumonia. Cefodizime (CEF) as an antibiotic is suspected to enhance host resistance against various microbial invasions through interactions with bacteria and host cells. To investigate the influence of CEF on the pulmonary response to Klebsiella that does not merely result from direct bacterial clearance by the drug, we inoculated mice with heat-killed fluorescein isothiocyanate-labeled K. pneumoniae. CEF upregulated (P < 0.01) the early Klebsiella-induced secretion of tumor necrosis factor alpha, as well as the number (P < 0.01) and phagocytic efficacy (P < 0.001) of alveolar macrophages. By contrast, the late polymorphonuclear neutrophil recruitment (P < 0.05) and levels of interleukin-1 alpha (IL-1?) (P < 0.05) and IL-6 (P < 0.05) were reduced. The stimulation of an early immune response by CEF followed by late reduction in inflammation may be beneficial against bacterial pneumonia.

Bergeron, Yves; Deslauriers, Anne-Marie; Ouellet, Nathalie; Gauthier, Marie-Christine; Bergeron, Michel G.

1999-01-01

116

Ethanol from lignocellulosic wastes with utilization of recombinant bacteria.  

PubMed

This article presents the advanced technology that has been developed by BioEnergy International of Gainesville, Florida, utilizing novel recombinant strains of bacteria developed by Lonnie Ingram of the University of Florida. The first commercial applications of these unique fermenting organisms convert 5-carbon sugars, as well as 6-carbon sugars, and oligomers of cellulose (e.g., cellobiose and cellotriose) directly to ethanol. The proposed systems that will be utilized for conversion of agricultural wastes, mixed waste papers, and pulp and paper mill waste in forthcoming commercial installations are now under design. This involves the extensive experience of Raphael Katzen Associates International, Inc. in acid hydrolysis, enzyme production, enzymatic hydrolysis, large-scale fermentation engineering, and distillation/dehydration. Specific examples of this advanced technology will be presented in different applications, namely: 1. Conversion of the hemicellulose content of sugar cane bagasse to 5-carbon sugars by mild-acid prehydrolysis, followed by fermentation of the 5-carbon sugar extract with recombinant Escherichia coli in a commercial installation soon to be under construction in Brazil. This unique process utilizes the surplus hemicellulose fraction of bagasse not required for steam and power generation to produce ethanol, additional to that from the original can juice, which has been converted by conventional sucrose fermentation to ethanol. The process also recovers and converts to ethanol the majority of sucrose normally lost with the bagasse fibers. Resultant beer is enriched in an innovative process to eliminate the need for incremental rectification capacity. 2. Application of this technology to mixed waste paper in Florida, with a moderate loading of newsprint (85% mechanical wood fiber), will involve a mild-acid prehydrolysis, the partial extraction of the 5-carbon sugars produced from hemicellulose as a feedstock for propagation of the recombinant Klebsiella oxytoca bacterium. Included is a facility providing for in-house production of cellulase enzyme, as an active whole broth for direct use in simultaneous saccharification and fermentation (SSF) of the remaining cellulose and residual 5-carbon sugars to ethanol. This is followed by distillation and dehydration in the advanced commercially available low-energy recovery system. 3. Another potential application of this unique technology involves utilization of a variety of wastes from several pulp and paper mills in close proximity, permitting collection of these wastes at low cost and reducing the considerable cost encountered in disposing of such low-energy wet waste.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8010771

Katzen, R; Fowler, D E

1994-01-01

117

Methionine-to-Cysteine Recycling in Klebsiella aerogenes  

PubMed Central

In the enteric bacteria Escherichia coli and Salmonella enterica, sulfate is reduced to sulfide and assimilated into the amino acid cysteine; in turn, cysteine provides the sulfur atom for other sulfur-bearing molecules in the cell, including methionine. These organisms cannot use methionine as a sole source of sulfur. Here we report that this constraint is not shared by many other enteric bacteria, which can use either cysteine or methionine as the sole source of sulfur. The enteric bacterium Klebsiella aerogenes appears to use at least two pathways to allow the reduced sulfur of methionine to be recycled into cysteine. In addition, the ability to recycle methionine on solid media, where cys mutants cannot use methionine as a sulfur source, appears to be different from that in liquid media, where they can. One pathway likely uses a cystathionine intermediate to convert homocysteine to cysteine and is induced under conditions of sulfur starvation, which is likely sensed by low levels of the sulfate reduction intermediate adenosine-5?-phosphosulfate. The CysB regulatory proteins appear to control activation of this pathway. A second pathway may use a methanesulfonate intermediate to convert methionine-derived methanethiol to sulfite. While the transsulfurylation pathway may be directed to recovery of methionine, the methanethiol pathway likely represents a general salvage mechanism for recovery of alkane sulfide and alkane sulfonates. Therefore, the relatively distinct biosyntheses of cysteine and methionine in E. coli and Salmonella appear to be more intertwined in Klebsiella.

Seiflein, Thomas A.; Lawrence, Jeffrey G.

2001-01-01

118

Enzymatic Degradation of Polygalacturonic Acid by Yersinia and Klebsiella Species in Relation to Clinical Laboratory Procedures  

PubMed Central

As scored by several specified plating procedures, clinical and environmental strains of Yersinia enterocolitica, Yersinia pseudotuberculosis, and Klebsiella pneumoniae “Oxytocum” showed detectable, albeit generally weak, ability to digest polygalacturonic (pectic) acid. None of these bacterial strains had the vigorous and rapid pectolytic activity on these polygalacturonic acid-containing media that is typical of soft-rot Erwinia species, although some of the Oxytocum strains came fairly close. Analyses of the pectolytic enzyme contents of the cells and culture supernatants of the Yersinia and Klebsiella species revealed that readily detectable quantities of cell-bound polygalacturonic acid trans-eliminase and hydrolytic polygalacturonase were formed by the Yersinia and Klebsiella species; however, the total units of enzyme activity produced by these bacteria were, in general, lower than were produced by soft-rot Erwinia species. Furthermore, unlike the situation in soft-rot Erwinia cultures, these pectolytic enzymes of Yersinia and Klebsiella species were not excreted rapidly and massively into the growth medium. Cultures of other enterobacteria (Citrobacter species, Enterobacter species, Erwinia amylovora, Erwinia herbicola, Escherichia coli, Proteus species, Salmonella typhimurium, and Serratia marcescens) showed no pectolytic ability whatsoever by any of the plating procedures used and (to the extent they were so examined) produced no pectolytic enzymes detectable either in their cells or culture supernatants. This slow or weak release of pectolytic enzymes by Yersinia and Klebsiella species has a bearing on clinical laboratory procedures suitable for detecting their pectolytic activity; methods adequate for this purpose are detailed.

Starr, Mortimer P.; Chatterjee, Arun K.; Starr, Phoebe B.; Buchanan, Gordon E.

1977-01-01

119

Regulatory region of the Klebsiella aerogenes tryptophan operon.  

PubMed Central

The trp operon of Klebsiella aerogenes was cloned, and its regulatory region was sequenced. Comparison with previously reported trp regulatory sequences of other enteric bacteria indicates that the K. aerogenes trp promoter-operator region is most similar to the corresponding region of Salmonella typhimurium. The trp leader regions of K. aerogenes and other enteric bacteria are organized similarly, but there are significant differences in the stabilities of the predicted secondary structures in their leader transcripts. These differences should make the K. aerogenes attenuator a weaker transcription termination site than any of the other attenuator regions studied; this was confirmed in in vitro transcription experiments. The sequence of the leader transcript and the precise site of in vitro termination were determined. Images

Blumenberg, M; Yanofsky, C

1982-01-01

120

Emergence of Carbapenemaseproducing Klebsiella Pneumoniae of Sequence type 258 in Michigan, USA.  

PubMed

The prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in our hospital increased beginning in 2009. We aimed to study the clinical and molecular epidemiology of these emerging isolates. We performed a retrospective review of all adult patients with clinical cultures confirmed as CPE by positive modified Hodge test from 5/2009- 5/2010 at the University of Michigan Health System (UMHS). Clinical information was obtained from electronic medical records. Available CPE isolates were analyzed by polymerase chain reaction (PCR) and sequencing of the 16S rRNA encoding gene and bla KPC locus. Multilocus sequence typing (MLST) was used to characterize Klebsiella pneumoniae isolates. Twenty six unique CPE isolates were obtained from 25 adult patients. The majority were Klebsiella pneumoniae (n=17). Other isolates included K. oxytoca (n=3), Citrobacter freundii (n=2), Enterobacter cloacae (n=2), Enterobacter aerogenes (n=1) and Escherichia coli (n=1). Molecular characterization of 19 available CPE isolates showed that 13 (68%) carried the KPC-3 allele and 6 (32%) carried the KPC-2 allele. Among 14 available K. pneumoniae strains, 12 (86%) carried the KPC-3 allele and belonged to a common lineage, sequence type (ST) 258. The other 2 (14%) K. pneumoniae isolates carried the KPC-2 allele and belonged to two unique STs. Among these ST 258 strains, 67% were isolated from patients with prior exposures to health care settings outside of our institution. In contrast, all CPE isolates carrying the KPC-2 allele and all non ST 258 CPE isolates had acquisition attributable to our hospital. Molecular epidemiology of carbapenemase producing K. pneumoniae suggests that KPC-3 producing K. pneumoniae isolates of a common lineage, sequence type (ST 258), are emerging in our hospital. While ST 258 is a dominant sequence type throughout the United States, this study is the first to report its presence in Michigan. PMID:24470956

Jain, Ruchika; Walk, Seth T; Aronoff, David M; Young, Vincent B; Newton, Duane W; Chenoweth, Carol E; Washer, Laraine L

2013-01-22

121

Frequency assessment of ?-lactamase enzymes in Escherichia coli and Klebsiella isolates in patients with urinary tract infection  

PubMed Central

Background: Production of ?-lactamase enzymes is the most common and important mechanism of resistance in Gram-negative bacteria. The objective of this study was to assess frequency of three main ?-lactamase enzymes, including extended spectrum ?-lactamases (ESBLs), metallo-?-lactamase (MBL), and Klebsiella pneumoniae carbapenemase (KPC) enzymes in Escherichia coli and Klebsiella spp. isolated from nosocomial and community urinary tract infections (UTI). Materials and Methods: In a cross-sectional study from March to December 2012, midstream urine samples were obtained from patients suspicious of UTI who were hospitalized or referred to Al-Zahra Hospital, Isfahan, Iran. Samples were cultured and E. coli and Klebsiella spp. were isolated. Prevalence of ESBLs, KPC, and MBLs producing E. coli and Klebsiella spp. were studied by double-disk (combined-disk), the modified Hodge test and imipenem-ethylenediaminetetraacetic acid combined disc methods respectively. In addition, their antimicrobial susceptibility patterns determined and resistant to carbapenem drugs confirmed by minimum inhibitory concentrations based on E-test method. Results: A total of 1080 E. coli and 484 Klebsiella strains were isolated during study period. Among 720 E. coli and 384 Klebsiella isolates from hospitalized patients, 300 (41.7%) and 198 (51.5%) were ESBLs producers, respectively. In out-patients samples, the rate of ESBLs production was 25% (90/360) and 40% (40/100) in E. coli and Klebsiella isolates, respectively. Prevalence of MBLs producing in hospital E. coli and Klebsiella isolates were 0.3% (2/720) and 2.6% (10/384), and for KPC data were 1.4% (10/720) and 48.4% (186/384), respectively. No MBLs and KPC producing isolate was seen in non-hospital E. coli and Klebsiella isolates except for one non-hospital KPC producing Klebsiella isolate. Conclusion: The result of our study showed high prevalence of ESBLs and KPC, but low prevalence of MBLs in cultured bacteria from urine samples of patients with acute UTI. In addition, KPC was the main carbapenem resistance mechanism in Klebsiella and E. coli isolates.

Moayednia, Reza; Shokri, Dariush; Mobasherizadeh, Sina; Baradaran, Azar; Fatemi, Seyed Masih; Merrikhi, Alireza

2014-01-01

122

Enterobacter and Klebsiella species isolated from fresh vegetables marketed in Valencia (Spain) and their clinically relevant resistances to chemotherapeutic agents.  

PubMed

Occurrence of antibiotic-resistant pathogenic or commensal enterobacteria in marketed agricultural foodstuffs may contribute to their incorporation into the food chain and constitutes an additional food safety concern. In this work, we have determined the clinically relevant resistances to 11 common chemotherapeutic agents in Enterobacter and Klebsiella isolates from fresh vegetables from various sources (supermarkets and greengrocers' shops in Valencia, Spain). A total of 96 isolates were obtained from 160 vegetables analyzed (50% positive samples): 68 Enterobacter isolates (59 E. cloacae, two E. aerogenes, two E. cancerogenus, one E. gergoviae, and four E. sakazakii, currently Cronobacter spp.), and 28 Klebsiella isolates (19 K. oxytoca and 9 K. pneumoniae). Only seven isolates were susceptible to all agents tested, and no resistances to ceftazidime, ciprofloxacin, gentamicin, and chloramphenicol were detected. Most isolates were resistant to amoxicillin/clavulanic acid (74 [58 Enterobacter and 16 Klebsiella]) or to ampicillin (80 [55/25]). Other resistances were less frequent: nitrofurantoin (13 isolates [12/1]), tetracycline (6 [5/1]), co-trimoxazole (3 [3/0]), cefotaxime (1 [1/0]), and streptomycin (2 [1/1]). Multiresistant isolates to two (56 [41/15]), three (10 E. cloacae isolates), four (one E. cloacae and one K. pneumoniae isolate), and five (two E. cloacae isolates) chemotherapeutic agents were also detected. The presence of potential pathogens points to marketed fresh produce, which often is eaten raw, as a risk factor for consumer health. In addition, these results support the usefulness of these bacterial species as indicators of the spreading of antibiotic resistances into the environment, particularly in the food chain, and suggest their role as carriers of resistance determinants from farms to consumers, which may constitute an additional "silent" food safety concern. Therefore, there is a need to improve the hygienic quality of marketed fresh vegetables, from better methods to prevent contamination in the farms to the use of sanitizing practices at home. PMID:23980710

Falomir, María Pilar; Rico, Hortensia; Gozalbo, Daniel

2013-12-01

123

Binding to and Opsonophagocytic Activity of O-Antigen-Specific Monoclonal Antibodies against Encapsulated and Nonencapsulated Klebsiella pneumoniae Serotype O1 Strains  

Microsoft Academic Search

The high mortality of nosocomial infections caused by Klebsiella spp. has acted as a stimulus to develop immunotherapeutic approaches targeted against surface molecules of these bacteria. Since O-antigen-specific antibodies may add to the protective effect of K antisera, we tested the functional and binding capacity of O-antigen-specific monoclonal antibodies (MAbs) raised against different Klebsiella O antigens. The MAbs tested were

THOMAS K. HELD; NINA R. M. JENDRIKE; TOMISLAV RUKAVINA; RAINER PODSCHUN; MATTHIAS TRAUTMANN

2000-01-01

124

Nasopharyngeal Carriage of Klebsiella pneumoniae and Other Gram-Negative Bacilli in Pneumonia-Prone Age Groups in Semarang, Indonesia  

PubMed Central

Gram-negative bacilli (GNB) cause many cases of pneumonia in Indonesia. We investigated nasopharyngeal carriage of GNB in Semarang, Indonesia. Klebsiella pneumoniae carriage in adults (15%) was higher than in children (7%) (P = 0.004), while that of other GNB was comparable. Poor food and water hygiene are determinants of carriage of these bacteria.

Severin, Juliette A.; Gasem, M. Hussein; Keuter, Monique; van den Broek, Peterhans; Hermans, Peter W. M.; Wahyono, Hendro; Verbrugh, Henri A.

2013-01-01

125

Serine utilization by Klebsiella aerogenes.  

PubMed Central

Klebsiella aerogenes was found to contain a specific L-serine dehydrase that was induced by threonine, glycine or leucine, but not by its substrate. Cellular concentrations were sensitive to carbon rather than nitrogen sources in the growth medium. A nonspecific isoleucine-sensitive L-threonine dehydrase supplemented the specific L-serine dehydrase activity. K. aerogenes also contains a leucine-inducible L-threonine dehydrogenase which probably initiated a threonine-utilization pathway in which the serine-specific dehydrate participated. Strains that were altered in their ability to metabolize serine differed in either L-serine dehydrase or L-threonine dehydrase activity. Thus, K. aerogenes growing on L-serine as a sole nitrogen source relies upon two enzymes that metabolize the amino acid as subsidiary functions.

Vining, L C; Magasanik, B

1981-01-01

126

Electricity generation from glucose by a Klebsiella sp. in microbial fuel cells  

Microsoft Academic Search

As electrochemically active bacteria play an important role in microbial fuel cells (MFCs), it is necessary to get a comprehensive\\u000a understanding of their electrogenesis mechanisms. In this study, a new electrochemically active bacterium, Klebsiella sp. ME17, was employed into an “H” typed MFC for electrogenesis, with glucose as the electron donor. The maximum power density\\u000a was 1,209 mW\\/m2 at a resistance

Xue Xia; Xiao-xin Cao; Peng Liang; Xia Huang; Su-ping Yang; Gen-gui Zhao

2010-01-01

127

Clinical epidemiology of the global expansion of Klebsiella pneumoniae carbapenemases.  

PubMed

Klebsiella pneumoniae carbapenemases (KPCs) were originally identified in the USA in 1996. Since then, these versatile ?-lactamases have spread internationally among Gram-negative bacteria, especially K pneumoniae, although their precise epidemiology is diverse across countries and regions. The mortality described among patients infected with organisms positive for KPC is high, perhaps as a result of the limited antibiotic options remaining (often colistin, tigecycline, or aminoglycosides). Triple drug combinations using colistin, tigecycline, and imipenem have recently been associated with improved survival among patients with bacteraemia. In this Review, we summarise the epidemiology of KPCs across continents, and discuss issues around detection, present antibiotic options and those in development, treatment outcome and mortality, and infection control. In view of the limitations of present treatments and the paucity of new drugs in the pipeline, infection control must be our primary defence for now. PMID:23969216

Munoz-Price, L Silvia; Poirel, Laurent; Bonomo, Robert A; Schwaber, Mitchell J; Daikos, George L; Cormican, Martin; Cornaglia, Giuseppe; Garau, Javier; Gniadkowski, Marek; Hayden, Mary K; Kumarasamy, Karthikeyan; Livermore, David M; Maya, Juan J; Nordmann, Patrice; Patel, Jean B; Paterson, David L; Pitout, Johann; Villegas, Maria Virginia; Wang, Hui; Woodford, Neil; Quinn, John P

2013-09-01

128

Two-Center Collaborative Evaluation of Performance of the BD Phoenix Automated Microbiology System for Identification and Antimicrobial Susceptibility Testing of Gram-Negative Bacteria?  

PubMed Central

The performance of the BD Phoenix Automated Microbiology System (BD Diagnostic Systems, Sparks, MD) was assessed for identification (ID) and antimicrobial susceptibility testing (AST) of the majority of clinically encountered bacterial isolates in a European collaborative two-center trial. A total of 494 bacterial isolates including various species of the Enterobacteriaceae and 110 nonfermentative gram-negative bacteria were investigated: of these, 385 were single patient isolates, and 109 were challenge strains tested at one center. The performance of the Phoenix extended-spectrum ?-lactamase (ESBL) test was also evaluated for 203 strains of Escherichia coli, Klebsiella pneumoniae, and Klebsiella oxytoca included in the study. Forty-two antimicrobial drugs were tested, including members of the following drug classes: aminoglycosides, ?-lactam antibiotics, ?-lactam/?-lactamase inhibitors, carbapenems, cephems, monobactams, folate antagonists, quinolones, and others. Phoenix system ID results were compared to those of the laboratories' routine ID systems (API 20E and API CHE, ATB ID32E, ID32GN, and VITEK 2 [bioMérieux, Marcy l'Etoile, France]); Phoenix AST results were compared to those of frozen standard broth microdilution (SBM) panels according to NCCLS (now CLSI) guidelines (NCCLS document M100-S9, approved standard M7-A4). Discrepant results were repeated in duplicate. Concordant IDs of 98.4 and 99.1% were observed for the Enterobacteriaceae and the nonfermentative group, respectively. For AST results, the overall essential agreement was 94.2%; the category agreement was 97.3%; and the very major error rate, major error rate, and minor error rate were 1.6, 0.6, and 1.9%, respectively. In terms of ESBL detection, Phoenix results were 98.5% concordant with those of the reference system, with 98.0% sensitivity and 98.7% specificity. In conclusion, the Phoenix ID results showed high agreement with results of the systems to which they were being compared: the AST performance was highly equivalent to that of the SBM reference method, and the system proved to be very accurate for the detection of ESBL producers.

Menozzi, Maria Grazia; Eigner, Ulrich; Covan, Silvia; Rossi, Sabina; Somenzi, Pietro; Dettori, Giuseppe; Chezzi, Carlo; Fahr, Anne-Marie

2006-01-01

129

Klebsiella pneumoniae associated extreme plasmacytosis.  

PubMed

Infection-associated plasmacytosis is not uncommon; however, marked plasmacytosis in both peripheral blood and bone marrow that mimicks plasma cell leukemia is a very rare condition. We encountered a case of extreme plasmacytosis associated with Klebsiella pneumoniae sepsis in an aplastic anemia patient. A 42-year-old man presented with high fever of 5 days' duration. Hematological analysis revealed severe neutropenia and thrombocytopenia; his white blood cell count was 900/mm(3), with 26% of plasma and plasmacytoid cells in peripheral blood. Bone marrow biopsy and aspiration showed 25% cellularity with marked plasmacytosis (80%), highly suggestive of plasma cell leukemia. On the eighth hospital day, K. pneumoniae was identified in blood and sputum cultures. Fever improved after switching antibiotics, although his hematological condition worsened. His bone marrow cellularity (plasma cell proportion) progressively decreased: the values were 25% (80%), 10% (26%), 10% (11%), and < 10% (< 4%) on the 8th, 30th, 60th, and 90th hospital day, respectively. His plasmacytosis was extremely severe but was confirmed to be reactive with polyclonality. The present case represents the first report of strong suspicion of K. pneumoniae sepsis-associated marked plasmacytosis in an aplastic anemia patient. PMID:24475358

Moon, Yeonsook; Jang, Woo Ri; Yi, Hyeon Gyu; Park, In Seo; Nahm, Chung Hyun; Choi, Jong Weon; Kim, Jin Ju; Han, Seung Baik

2013-12-01

130

Development of industrial-medium-required elimination of the 2,3-butanediol fermentation pathway to maintain ethanol yield in an ethanologenic strain of Klebsiella oxytoca.  

PubMed

Fermentation efficiency and nutrient costs are both significant factors in process economics for the microbial conversion of cellulosic biomass to commodity chemicals such as ethanol. In this study, we have developed a more industrial medium (OUM1) composed of 0.5% corn steep liquor (dry weight basis) supplemented with mineral salts (0.2%), urea (0.06%), and glucose (9%). Although the growth of strain P2 was vigorous in this medium, approximately 14% of substrate carbon was diverted into 2,3-butanediol and acetoin under the low pH conditions needed for optimal cellulase activity during simultaneous saccharification. Deleting the central region of the budAB genes encoding alpha-acetolactate synthase and alpha-acetolactate decarboxylase eliminated the butanediol and acetoin coproducts and increased ethanol yields by 12%. In OUM1 medium at pH 5.2, strain BW21 produced over 4% ethanol in 48 h (0.47 g ethanol per g glucose). Average productivity (48 h), ethanol titer, and ethanol yield for BW21 in OUM1 medium (pH 5.2) exceeded that of the parent (strain P2) in rich laboratory medium (Luria broth). PMID:16209539

Wood, Brent E; Yomano, L P; York, S W; Ingram, L O

2005-01-01

131

Stability Analysis in a Model of 1,2-dichloroethane Biodegradation by Klebsiella Oxytoca va 8391Immobilized on Granulated Activated Carbon  

NASA Astrophysics Data System (ADS)

We consider an ecological model for biodegradation of toxic substances in aquatic and atmospheric biotic systems. The model, which is described by a nonlinear system of four ordinary differential equations, is known to be experimentally validated. We compute the equilibrium points of the model and study their asymptotic stability. The Maple package BifTools is used to calculate one- and two-parameter bifurcations of the equilibrium points.

Borisov, M.; Dimitrova, N.

2011-11-01

132

Detection of drug-resistant Klebsiella pneumoniae in Chinese hares (Lepus sinensis).  

PubMed

We investigated an outbreak of acute pneumonia among adult Chinese hares (Lepus sinensis) and diarrhea among juvenile hares in Hebei Province, China, in 2012. Diagnosis was based on necropsy examination, microbial characteristics, biochemical identification, and nucleotide sequence analysis. The isolated bacteria from tissue samples of dead hares were identified as Klebsiella pneumoniae ssp. pneumoniae (K. pneumoniae). This K. pneumoniae was resistant to the antimicrobials imipenem, meropenem, penicillin, and vancomycin, but was highly sensitive to cefepime, cotrimoxazole, and enrofloxacin. Klebsiella pneumoniae is an important opportunistic pathogen, which often causes nosocomial infections in immunocompromised patients. However, the emergence of drug-resistant K. pneumoniae in hares indicates the existence of increasing risk of pathogen transmission between humans and wildlife. Given the close association between wildlife, livestock, and humans, it is important to identify epidemiologic factors associated with infection in these hares to minimize the risk of K. pneumoniae transmission. PMID:24171575

Du, Yingchun; Luo, Jing; Wang, Chengmin; Wen, Qingna; Duan, Mingxing; Zhang, Hong; He, Hongxuan

2014-01-01

133

Hippurate Hydrolysis in Klebsiella-Cloaca Classification  

Microsoft Academic Search

SUMMARY: 169 strains of Klebsiella pneumoniae and 68 strains of Cloaca cloacae were used in an examination of Hajna & Damon's hippurate test and various modi- fications of it. The addition of a pH indicator (phenol red) to the medium enabled hydrolysis to be detected by a change of colour. Clear-cut distinction between K. pneumoniae and C. cloacae was not

MERIEL L. THIRST

1957-01-01

134

[Highly efficient transformation with plasmid DNA in Klebsiella pneumoniae].  

PubMed

Attempts to transform Klebsiella pneumoniae resulted in very low efficiencies because of capsule polysaccharide (CPS). It was reported that some chelating agents could reduce CPS production and improve transformation efficiency. These methods mentioned above could not improve transformation efficiency apparently by incorporating such agents to liquid medium. However, this method introduces a simple way for efficient transformation of K. pneumoniae. In this method, K. pneumoniae strains NTUH-K2044 and magA(-) mutant are envolved as recipients. The plasmids used in this way are composed of pIP843T, pIP843TdhaB, pIP843TdhaT with different sizes. The sole critical step is to harvest bacteria on LB plates to prepare competent cells. 150 +/- 10, 1.3 x 10(3) +/- 100, 2 x 10(5) +/- 300, and 3.4 x 10(7) +/- 500 transformants were obtained per microgram plasmid DNA with NTUH-K2044 liquid cells, magA(-) liquid cells, NTUH-K2044 solid cells, and magA(-) solid cells, respectively. The number of transformants per microg DNA obtained by electroplating solid cells is at least 10(3) fold higher than that of transformants with liquid-cultured bacteria. This method will benefit gene manipulation and genetic study in K. pneumoniae. PMID:17944381

Zheng, Yan; Liu, Xi-peng; Liu, Jian-hua

2007-08-01

135

Complete Genome Sequence of the N2Fixing Broad Host Range Endophyte Klebsiella pneumoniae 342 and Virulence Predictions Verified in Mice  

Microsoft Academic Search

We report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, Klebsiella pneumoniae 342. Although K. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world),

Derrick E. Fouts; Heather L. Tyler; Robert T. DeBoy; Sean Daugherty; Qinghu Ren; Jonathan H. Badger; Anthony S. Durkin; Heather Huot; Susmita Shrivastava; Sagar Kothari; Robert J. Dodson; Yasmin Mohamoud; Hoda Khouri; Luiz F. W. Roesch; Karen A. Krogfelt; Carsten Struve; Eric W. Triplett; Barbara A. Methé

2008-01-01

136

Emergence of resistant Klebsiella pneumoniae in the intestinal tract during successful treatment of Klebsiella pneumoniae lung infection in rats.  

PubMed

Antibiotic treatment of lung infections may lead to the emergence of resistance in the gut flora. Appropriate dosing regimens could mitigate this adverse effect. In gnotobiotic rats harboring intestinal Escherichia coli and Enterococcus faecium populations, a lung infection by Klebsiella pneumoniae was instigated with two different sizes of inoculum to represent an early or a late initiation of antibiotic treatment. The rats were treated with marbofloxacin, an expanded-spectrum fluoroquinolone, by a single-shot administration or a fractionated regimen over 4 days. Intestinal bacterial populations were monitored during and after treatment. At the infection site, bacterial cure without any selection of resistance was observed. Whatever the dosage regimen, fluoroquinolone treatment had a transient negative impact on the E. coli gut population but not on that of E. faecium. The intestinal flora was colonized by the pathogenic lung bacteria, and there was the emergence of intestine-resistant K. pneumoniae, occurring more often in animals treated with a single marbofloxacin dose than with the fractionated dose. Bacterial cure without resistance selection at the infection site with fluoroquinolone treatment can be linked to colonization of the digestive tract by targeted pulmonary bacteria, followed by the emergence of resistance. PMID:20457820

Kesteman, Anne-Sylvie; Perrin-Guyomard, Agnès; Laurentie, Michel; Sanders, Pascal; Toutain, Pierre-Louis; Bousquet-Mélou, Alain

2010-07-01

137

Emergence of Resistant Klebsiella pneumoniae in the Intestinal Tract during Successful Treatment of Klebsiella pneumoniae Lung Infection in Rats?  

PubMed Central

Antibiotic treatment of lung infections may lead to the emergence of resistance in the gut flora. Appropriate dosing regimens could mitigate this adverse effect. In gnotobiotic rats harboring intestinal Escherichia coli and Enterococcus faecium populations, a lung infection by Klebsiella pneumoniae was instigated with two different sizes of inoculum to represent an early or a late initiation of antibiotic treatment. The rats were treated with marbofloxacin, an expanded-spectrum fluoroquinolone, by a single-shot administration or a fractionated regimen over 4 days. Intestinal bacterial populations were monitored during and after treatment. At the infection site, bacterial cure without any selection of resistance was observed. Whatever the dosage regimen, fluoroquinolone treatment had a transient negative impact on the E. coli gut population but not on that of E. faecium. The intestinal flora was colonized by the pathogenic lung bacteria, and there was the emergence of intestine-resistant K. pneumoniae, occurring more often in animals treated with a single marbofloxacin dose than with the fractionated dose. Bacterial cure without resistance selection at the infection site with fluoroquinolone treatment can be linked to colonization of the digestive tract by targeted pulmonary bacteria, followed by the emergence of resistance.

Kesteman, Anne-Sylvie; Perrin-Guyomard, Agnes; Laurentie, Michel; Sanders, Pascal; Toutain, Pierre-Louis; Bousquet-Melou, Alain

2010-01-01

138

Capsule Impedes Adhesion to and Invasion of Epithelial Cells by Klebsiella pneumoniae  

PubMed Central

The adhesion of K21a, K26, K36, and K50 capsulated Klebsiella strains to ileocecal (HCT-8) and bladder (T24) epithelial cell lines was significantly lower than that of their corresponding spontaneous noncapsulated variants K21a/3, K26/1, K36/3, and K50/3, respectively. Internalization of the bacteria by both epithelial cell lines was also significantly reduced. Similarly, a capsule-switched derivative, K2(K36), that exhibited a morphologically larger K36 capsule and formed more capsular material invaded the ileocecal epithelial cell line poorly compared to the corresponding K2 parent strain. None of the capsulated strains exhibited significant mannose-sensitive type 1 fimbriae, whereas two of the noncapsulated variants K21a/3 and K50/3 exhibited potent mannose-sensitive hemagglutinating activity. Although hemagglutinating activity that could be attributed to mannose-resistant Klebsiella type 3 fimbriae was weak in all strains, in several cases the encapsulated parent strains exhibited lower titers than their corresponding noncapsulated variants. Although the level of adhesion to the ileocecal cells is not different from adhesion to bladder cells, bacterial internalization by bladder cells was significantly lower than internalization by ileocecal cells, suggesting that bladder cells lack components required for the internalization of Klebsiella.

Sahly, Hany; Podschun, Rainer; Oelschlaeger, Tobias A.; Greiwe, Michael; Parolis, Haralambos; Hasty, David; Kekow, Jorn; Ullmann, Uwe; Ofek, Itzhak; Sela, Shlomo

2000-01-01

139

Development of immunization trials against Klebsiella pneumoniae.  

PubMed

Klebsiella pneumoniae is the most common cause of nosocomial respiratory tract and premature intensive care infections, and the second most frequent cause of Gram-negative bacteraemia and urinary tract infections. Drug resistant isolates remain an important hospital-acquired bacterial pathogen, add significantly to hospital stays, and are especially problematic in high impact medical areas such as intensive care units. Many investigations worldwide proved the increasing resistance of such pathogen, resulting in an average rate of 1.63 outbreak every year. A variety of preventive measures were applied to reduce such incidences. Immunotherapy and passive immunization researches as well found their way to the treatment of Klebsiella. During the last 40 years, many trials for constructing effective vaccines were followed. This up-to-date review classifies such trials and documents them in a progressive way. A following comment discusses each group benefits and defects. PMID:22100884

Ahmad, Tarek A; El-Sayed, Laila H; Haroun, Medhat; Hussein, Ahmad A; El Ashry, El Sayed H

2012-03-23

140

[Construction of polyhydroxybutyrate pathway in Klebsiella pneumoniae].  

PubMed

1,3-propanediol production with the byproduct of biodiesel production is important to increase the economic benefit of biodiesel industry. Accumulation of 3-hydroxypropionaldehyde is one of the key problems in the 1,3-propanediol fermentation process, leading to the cell death and the fermentation abnormal ceasing. Different from the traditional way of reducing the accumulation of the 3-hydroxypropionaldehyde, we introduced the polyhydroxybutyrate pathway into the Klebsiella pneumoniae for the first time to enhance the tolerance of K. pneumoniae to 3-hydroxypropionaldehyde, at the same time, to improve the 1,3-propanediol production. Plasmid pDK containing phbC, phbA, phbB gene was constructed and transformed into K. pneumoniae successfully. PHB was detected in the engineered K. pneumoniae after IPTG induction and its content enhanced with the IPTG concentration increasing. The optimized IPTG concentration was 0.5 mmol/L. The constructed K. pneumoniae could produce 1,3-propanediol normally, at the same time accumulate polyhydroxybutyrate. With the constructed strain, the fermentation proceeds normally with the initial glucose was 70 g/L which the wild type strain stopped growing and the fermentation was ceasing; 1,3-propanediol concentration and yield reached 31.3 g/L and 43.9% at 72 h. Our work is helpful for the deep understanding of 1,3-propanediol metabolic mechanism of Klebsiella pneumoniae, and also provides a new way for strain optimization of Klebsiella pneumoniae. PMID:24432665

Guo, Xiaochen; Liu, Hongjuan; Wang, Yanping; Zhang, Jian'an; Liu, Dehua

2013-10-01

141

OCCURRENCE, SIGNIFICANCE, AND DETECTION OF 'KLEBSIELLA' IN WATER SYSTEMS  

EPA Science Inventory

Widespread occurrences of Klebsiella in water distribution networks have resulted in much discussion about the organism's effect on public health and about action that should be taken when Klebsiella is detected in public water supplies. Results obtained during development and te...

142

O-antigen seroepidemiology of Klebsiella clinical isolates and implications for immunoprophylaxis of Klebsiella infections.  

PubMed Central

To provide a database for the development of an O-antigen-polysaccharide-containing vaccine against Klebsiella spp., we examined the O-antigen seroepidemiology of 378 Klebsiella clinical isolates collected prospectively in two university centers. Strains were typed by competitive enzyme-linked immunosorbent assay with rabbit antisera specific for serogroups O1 to O12 and monoclonal antibodies (MAbs) specific for serogroups O1, O2ab, O2ac, and the genus-specific core antigen. The numbers of isolates (percentages) of individual O serogroups were as follows: 148 (39.2) for serogroup O1, 40 (10.6) for serogroup O2ab, 4 (1.1) for serogroup O2ac, 89 (23.6) for serogroup O3, 2 (0.5) for serogroup O4, 32 (8.5) for serogroup O5, none for serogroups O7, O9, and O12, and 21 (5.6) for serogroup O11. Forty-two (11.1) of the strains were non-O-typeable. O-serogroup distributions were virtually identical between isolates from invasive infections and those from noninvasive infections or colonizations. A vaccine containing the O-specific polysaccharides of serogroups O1, O2ab, O3, and O5 would cover 82% of clinically occurring O-antigen specificities. Three hundred thirty-eight of 378 isolates (89.4%) reacted with the genus-specific MAb V/9-5, which recognizes an epitope of the outer core region of Klebsiella lipopolysaccharide. Antibodies directed against this epitope may represent a further alternative for O-antigen-targeted immunoprophylaxis of Klebsiella infections. These data support further experimental investigations on the protective potential of O-antigen-based vaccines and/or hyperimmune globulins in Klebsiella infection.

Trautmann, M; Ruhnke, M; Rukavina, T; Held, T K; Cross, A S; Marre, R; Whitfield, C

1997-01-01

143

Normal anti-Klebsiella lymphocytotoxicity in ankylosing spondylitis  

SciTech Connect

We compared in vitro lymphocytotoxicity (LCT) of peripheral blood lymphocytes (PBL), obtained from patients with ankylosing spondylitis (AS) and normal controls (NC). Assays were performed with antibacterial antisera prepared from AS- and NC-derived Klebsiella and coliforms Escherichia coli. LCT assessed by eosin staining was not significantly different in PBL of 12 AS patients and 28 controls when reacted with 3 Klebsiella and 1 E coli antisera. LCT assessed by /sup 51/Cr release was not significantly different for PBL of 20 age- and sex-matched pairs of AS patients and NC when reacted with 3 Klebsiella and 1 E coli antisera. Similarly, LCT-/sup 51/Cr of PBL of 15 matched AS and NC pairs was not significantly different for anti-K21, a serotype putatively implicated in Klebsiella-HLA-B27 antigenic cross-reactivity. Our results do not support the notion of molecular mimicry between Klebsiella and B27 in the pathogenesis of primary AS.

Kinsella, T.D.; Fritzler, M.J.; Lewkonia, R.M.

1986-03-01

144

Hands as route of transmission for Klebsiella species.  

PubMed Central

Seventeen per cent of the staff of an intensive care ward were found to have Klebsiella spp contaminating their hands, and these strains could be related to serotypes infecting or colonising patients in the ward on the same day. We identified some simple ward procedures that resulted in contamination of nurses' hands with 100-1000 klebsiellae per hand. Klebsiellae survived on artifically inoculated hands for up to 150 minutes. Handwashing with chlorhexidine hand cleanser reliably gave 98-100% reduction in hand counts, and the introduction of routine handwashing by staff before moving from one patient to the next was associated with a significant and sustained reduction in the number of patients colonised or infected with Klebsiella spp. Staff clothing was occasionally contaminated, but ward air and dust rarely contained klebsiellae.

Casewell, M; Phillips, I

1977-01-01

145

Anti-Biofilm Activity: A Function of Klebsiella pneumoniae Capsular Polysaccharide  

PubMed Central

Competition and cooperation phenomena occur within highly interactive biofilm communities and several non-biocides molecules produced by microorganisms have been described as impairing biofilm formation. In this study, we investigated the anti-biofilm capacities of an ubiquitous and biofilm producing bacterium, Klebsiella pneumoniae. Cell-free supernatant from K. pneumoniae planktonic cultures showed anti-biofilm effects on most Gram positive bacteria tested but also encompassed some Gram negative bacilli. The anti-biofilm non-bactericidal activity was further investigated on Staphylococcus epidermidis, by determining the biofilm biomass, microscopic observations and agglutination measurement through a magnetic bead-mediated agglutination test. Cell-free extracts from K. pneumoniae biofilm (supernatant and acellular matrix) also showed an influence, although to a lesser extend. Chemical analyses indicated that the active molecule was a high molecular weight polysaccharide composed of five monosaccharides: galactose, glucose, rhamnose, glucuronic acid and glucosamine and the main following sugar linkage residues [?2)-?-l-Rhap-(1?]; [?4)-?-l-Rhap-(1?]; [?-d-Galp-(1?]; [?2,3)-?-d-Galp-(1?]; [?3)-?-d-Galp-(1?] and, [?4)-?-d-GlcAp-(1?]. Characterization of this molecule indicated that this component was more likely capsular polysaccharide (CPS) and precoating of abiotic surfaces with CPS extracts from different serotypes impaired the bacteria-surface interactions. Thus the CPS of Klebsiella would exhibit a pleiotropic activity during biofilm formation, both stimulating the initial adhesion and maturation steps as previously described, but also repelling potential competitors.

Dos Santos Goncalves, Marina; Delattre, Cedric; Balestrino, Damien; Charbonnel, Nicolas; Elboutachfaiti, Redouan; Wadouachi, Anne; Badel, Stephanie; Bernardi, Thierry; Michaud, Philippe; Forestier, Christiane

2014-01-01

146

Small molecule suppression of carbapenem resistance in NDM-1 producing Klebsiella pneumoniae  

PubMed Central

The already considerable global public health threat of multi-drug resistant Gram-negative bacteria has become even more of a concern following the emergence of New-Delhi metallo-?-lactamase (NDM-1) producing strains of Klebsiella pneumoniae and other Gram-negative bacteria. As an alternative approach to the traditional development of new bactericidal entities, we have identified a 2-aminoimidazole derived small molecule that acts as an antibiotic adjuvant and is able to suppress resistance of a NDM-1 producing strain of K. pneumoniae to imipenem and meropenem, in addition to suppressing resistance of other ?-lactam non-susceptible K. pneumoniae strains. The small molecule is able to lower carbapenem minimum inhibitory concentrations by up to 16-fold while exhibiting little bactericidal activity itself.

Worthington, Roberta J.; Bunders, Cynthia A.; Reed, Catherine S.; Melander, Christian

2012-01-01

147

Effects of prevalent freshwater chemical contaminants on in vitro growth of Escherichia coli and Klebsiella pneumoniae.  

PubMed

Many surface and ground waters in the continental US are contaminated with a variety of chemical pollutants, which are usually present in concentrations in the ppm and ppb range. The effects of these pollutants on coliform bacteria, which are prominent members of the aquatic flora, are poorly understood. Using a microtiter plate assay, isolates of Escherichia coli (from chicken intestine and fresh water), and an isolate of Klebsiella pneumoniae (from bovine milk) were exposed to varying concentrations of common pollutants over a 24 h period. The herbicides/pesticides simazine, atrazine, and diazinon; the VOCs trichloroethene and MTBE; the estrogens estradiol and estrone; and caffeine, all failed to inhibit bacterial growth at ppm levels. Only ethylene glycol, and the herbicide 2,4-D, significantly inhibited bacterial growth compared to controls. These results suggest that the replication of coliform bacteria in fresh waters is not adversely impacted by many common pollutants. PMID:17681655

Higgins, James; Hohn, Christina

2008-03-01

148

Anaerobic bacteria  

MedlinePLUS

Anaerobic bacteria are bacteria that do not live or grow in the presence of oxygen. In humans, ... Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's ...

149

IgG and IgA immune response against klebsiella in HLA-B27-associated anterior uveitis.  

PubMed Central

Enteric infections with Gram-negative bacteria are thought to play an important part in HLA-B27-associated disease such as Reiter's syndrome and reactive arthritis. But the role of bacterial infections in HLA-B27-positive ankylosing spondylitis (AS) and acute anterior uveitis (AU) is still controversial. A special interest has recently been devoted to the role of klebsiella infection in HLA-B27-associated disease. We studied the humoral immune response against a 'cross-reactive' strain of Klebsiella pneumoniae in 62 patients with anterior uveitis and 33 healthy controls. The anterior uveitis patients were subdivided into 25 HLA-B27-negative patients without AS (B27- AU+ AS-), 17 HLA-B27-positive patients without ankylosing spondylitis (B27+ AU+ AS-), and 19 HLA-B27-positive patients with ankylosing spondylitis (B27+ AU+ AS+). Total serum IgA was higher in patients than in controls in both the B27+ AU+ AS+ and B27+ AU+ AS- patients but not in the B27- AU+ AS- group. No abnormalities were observed in the total serum IgG levels. The level of both the IgG and IgA klebsiella antibodies did not differ in the various patient groups tested as compared with the controls. Comparisons between the patient groups showed that the IgG anti-klebsiella response was higher in B27-positive patients patients without AS than in those with AS. These results suggest that stimulation of mucosal surfaces may play a role in HLA-B27-associated anterior uveitis. Whether klebsiella organisms are involved in this stimulation remains unclear.

Kijlstra, A; Luyendijk, L; van der Gaag, R; van Kregten, E; Linssen, A; Willers, J M

1986-01-01

150

Biodegradation potential of pure and mixed bacterial cultures for removal of 4-nitroaniline from textile dye wastewater  

Microsoft Academic Search

Environmentally toxic aromatic amines including nitroanilines are commonly generated in dye contaminated wastewater in which azo dyes undergo degradation under anaerobic conditions. The aim of this study was to develop a process for biological treatment of 4-nitroaniline. Three bacteria identified as Acinetobacter sp., Citrobacter freundii and Klebsiella oxytoca were isolated from enrichment cultures of activated sludge on 4-nitroaniline, after which

Azeem Khalid; Muhammad Arshad; David E. Crowley

2009-01-01

151

Impact of pH on bacterial growth and activity of recent fluoroquinolones in pooled urine  

Microsoft Academic Search

Acidification of urine is widely recommended for prevention and treatment of urinary tract infections. We set out to describe the effect of modification of pH on bacterial growth of relevant bacteria as well as on activity of modern fluoroquinolones in urine in vitro. Bacterial growth of Escherichia coli ATCC 25922 and Klebsiella oxytoca ATCC 700324 was determined in pooled human

Zeynep Erdogan-Yildirim; Angela Burian; Mohammad Manafi; Markus Zeitlinger

2011-01-01

152

Mercury and organomercurial resistance in bacteria isolated from freshwater fish of wetland fisheries around Calcutta  

Microsoft Academic Search

Mercury-resistant bacteria belonging to the genera Bacillus, Escherichia, Klebsiella, Micrococcus, Pseudomonas, Salmonella, Sarcina, Shigella, Staphylococcus and Streptococcus were isolated from gills and guts of fresh water fish collected from wetland fisheries around Calcutta, India, contaminated with mercury compounds. The total number of bacteria, as well as Hg-resistant bacteria, were always higher in guts than gills. Bottom-dwelling fish contained higher number

Provash Chandra Sadhukhan; S. Ghosh; J. Chaudhuri; D. K. Ghosh; A. Mandal

1997-01-01

153

Capsular Types of Klebsiella pneumoniae Revisited by wzc Sequencing  

PubMed Central

Capsule is an important virulence factor in bacteria. A total of 78 capsular types have been identified in Klebsiella pneumoniae. However, there are limitations in current typing methods. We report here the development of a new genotyping method based on amplification of the variable regions of the wzc gene. Fragments corresponding to the variable region of wzc were amplified and sequenced from 76 documented capsular types of reference or clinical strains. The remaining two capsular types (reference strains K15 and K50) lacked amplifiable wzc genes and were proven to be acapsular. Strains with the same capsular type exhibited ?94% DNA sequence identity across the variable region (CD1-VR2-CD2) of wzc. Strains with distinct K types exhibited <80% DNA sequence identity across this region, with the exception of three pairs of strains: K22/K37, K9/K45, and K52/K79. Strains K22 and K37 shared identical capsular polysaccharide synthesis (cps) genes except for one gene with a difference at a single base which resulted in frameshift mutation. The wzc sequences of K9 and K45 exhibited high DNA sequence similarity but possessed different genes in their cps clusters. K52 and K79 exhibited 89% wzc DNA sequence identity but were readily distinguished from each other at the DNA level; in contrast, strains with the same capsular type as K52 exhibited 100% wzc sequence identity. A total of 29 strains from patients with bacteremia were typed by the wzc system. wzc DNA sequences confirmed the documented capsular type for twenty-eight of these clinical isolates; the remaining strain likely represents a new capsular type. Thus, the wzc genotyping system is a simple and useful method for capsular typing of K. pneumoniae.

Pan, Yi-Jiun; Lin, Tzu-Lung; Chen, Yen-Hua; Hsu, Chun-Ru; Hsieh, Pei-Fang; Wu, Meng-Chuan; Wang, Jin-Town

2013-01-01

154

CHARACTERISTICS OF KLEBSIELLA FROM TEXTILE FINISHING PLANT EFFLUENTS  

EPA Science Inventory

Klebsiella strains are found in abnormally high numbers in a stream receiving wastewater from a textile finishing plant. Representative strains are randomly selected to determine biochemical, serotype, and virulence patterns. All strains conform to the commonly accepted biochemic...

155

'Klebsiella' Densities in Waters Receiving Wood Pulp Effluents.  

National Technical Information Service (NTIS)

Surface waters receiving pulp mill effluents were examined for the presence of total coliforms, fecal coliforms, and Salmonella species. Fecal coliforms were biochemically identified as belonging to the Escherichia, Klebsiella or Enterobacter genera. Sixt...

B. E. Huntley A. C. Jones V. J. Cabelli

1976-01-01

156

Structure of the capsular polysaccharide of Klebsiella serotype K53.  

PubMed

Klebsiella serotype K53 is one of three strains belonging to the chemotype whose capsular polysaccharides consist of D-glucuronic acid, D-galactose, D-mannose, and L-rhamnose residues, and the structure of its polysaccharide was found to be of the "5 + 1 type" shown, of the same structural pattern as the capsule from Klebsiella K52 (Formula, see text). Nimmich has analyzed the capsular polysaccharide of Klebsiella K53 and has shown that it belongs to the chemotype that also comprises K40 and K80. As part of our continuing investigation of these polysaccharides, we now report the structure of the capsular antigen of Klebsiella K53; the structures of those from K40 and K80 are, at present, unknown. PMID:7438136

Dutton, G G; Paulin, M

1980-12-01

157

Risk Factors for Fecal Carriage of Extended-Spectrum Beta-Lactamase Producing Escherichia coli and Klebsiella spp. in the Community  

Microsoft Academic Search

Aim: Community-acquired infections caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria are an emerging problem. Digestive tract colonization is a prerequisite for infections by ESBL-producing microorganisms. The aim of this study was to determine the prevalence of and risk factors for fecal carriage of ESBL-producing Escherichia coli (E. coli) or Klebsiella spp. in the community. Materials and Methods: A total of 928

Özlem KURT AZAP; Hande ARSLAN; Turhan TOGAN

158

Enzymatic degradation of urinary indoxyl sulfate by Providencia stuartii and Klebsiella pneumoniae causes the purple urine bag syndrome.  

PubMed

The etiology of the purple urine bag syndrome (PUBS), in which the urinary catheter bag of some elderly patients develops intense purple coloration, was studied. The purple was found to be a mixture of indirubin dissolved in the plastic and indigo on its surface. Six patients with PUBS were studied, and Providencia stuartii was isolated from the urine of five and Klebsiella pneumoniae was isolated from the urine of one. These strains produced indigo in 7.9 mM indoxyl sulfate-containing agar. One hundred and fifty isolates of 41 species of bacteria were tested for their ability to produce indigo on agar containing indoxyl sulfate, but only 17 of 27 strains of P. stuartii, a single strain of Klebsiella pneumoniae, and Enterobacter agglomerans were positive. All of the indigo-producing bacteria had an indoxyl phosphatase with a pI of 6.4. This enzyme also possessed indoxyl sulfatase activity and was not present in strains that were unable to produce indigo from indoxyl sulfate. We conclude that PUBS results from the decomposition of urinary indoxyl sulfate to indigo and indirubin by bacteria (notably P. stuartii). As elderly catheterized patients often have high urinary indoxyl sulfate levels and colonization of their urinary tract with P. stuartii, the condition is most commonly seen in them. PMID:2846640

Dealler, S F; Hawkey, P M; Millar, M R

1988-10-01

159

Enzymatic degradation of urinary indoxyl sulfate by Providencia stuartii and Klebsiella pneumoniae causes the purple urine bag syndrome.  

PubMed Central

The etiology of the purple urine bag syndrome (PUBS), in which the urinary catheter bag of some elderly patients develops intense purple coloration, was studied. The purple was found to be a mixture of indirubin dissolved in the plastic and indigo on its surface. Six patients with PUBS were studied, and Providencia stuartii was isolated from the urine of five and Klebsiella pneumoniae was isolated from the urine of one. These strains produced indigo in 7.9 mM indoxyl sulfate-containing agar. One hundred and fifty isolates of 41 species of bacteria were tested for their ability to produce indigo on agar containing indoxyl sulfate, but only 17 of 27 strains of P. stuartii, a single strain of Klebsiella pneumoniae, and Enterobacter agglomerans were positive. All of the indigo-producing bacteria had an indoxyl phosphatase with a pI of 6.4. This enzyme also possessed indoxyl sulfatase activity and was not present in strains that were unable to produce indigo from indoxyl sulfate. We conclude that PUBS results from the decomposition of urinary indoxyl sulfate to indigo and indirubin by bacteria (notably P. stuartii). As elderly catheterized patients often have high urinary indoxyl sulfate levels and colonization of their urinary tract with P. stuartii, the condition is most commonly seen in them. Images

Dealler, S F; Hawkey, P M; Millar, M R

1988-01-01

160

Clinical and microbiological characteristics of tigecycline non-susceptible Klebsiella pneumoniae bacteremia in Taiwan  

PubMed Central

Background Resistance among Klebsiella pneumoniae to most antibiotics is on the rise. Tigecycline has been considered as one of the few therapeutic options available to treat multidrug-resistant bacteria. We investigated the clinical and microbiological characteristics of tigecycline non-susceptible K. pneumoniae bacteremia. Methods Adult patients with tigecycline non-susceptible K. pneumoniae bacteremia at a medical center in Taiwan over a 3-year period were enrolled. K. pneumoniae isolates were identified by the E-test using criteria set by the US Food and Drug Administration (FDA). Data on the clinical features of patients were collected from medical records. Genes for ?-lactamases, antimicrobial susceptibilities and pulsed-field gel electrophoresis (PFGE) results were determined for all isolates. Results Of 36 patients, 27 had nosocomial bacteremia. Overall 28-day mortality was 38.9%. The MIC50 and MIC90 of tigecycline were 6 and 8 mg/L, respectively. No carbapenemase was detected among the 36 isolates. Twenty isolates carried extended spectrum ?-lactamases and/or DHA-1 genes. No major cluster of isolates was found among the 36 isolates by PFGE. Intensive care unit onset of tigecycline non-susceptible Klebsiella pneumoniae bacteremia was the only independent risk factor for 28-day mortality. Conclusions The high mortality of patients with tigecycline non-susceptible K. pneumoniae bacteremia may suggest a critical problem. Further study to identify the possible risk factors for its development and further investigation of this type of bacteremia is necessary.

2014-01-01

161

Extended-Spectrum ?-Lactamase CTX-M-15-Producing Klebsiella pneumoniae of Sequence Type ST274 in Companion Animals  

PubMed Central

Screening of extended-spectrum ?-lactamase (ESBL)-producing Gram-negative bacteria in companion animals living in the Paris area in France identified a high rate of CTX-M-15-producing Klebsiella pneumoniae. Those isolates were recovered during the 2010-2011 period from both infections and asymptomatic colonizations. Sequence typing revealed that most of these isolates belonged to sequence type ST274. Interestingly, the blaCTX-M-15 gene was located on a specific and novel plasmid scaffold. These findings highlight that companion animals may be reservoirs for CTX-M-15-producing K. pneumoniae evolving separately from the human reservoir of CTX-M-15 producers.

Poirel, Laurent; Ducroz, Sebastien; Boulouis, Henri-Jean; Arne, Pascal; Millemann, Yves

2013-01-01

162

Controlled Expression in Klebsiella pneumoniae and Shigella flexneri Using a Bacteriophage P1-Derived C1-Regulated Promoter System  

PubMed Central

The utility of promoters regulated by the bacteriophage P1 temperature-sensitive C1 repressor was examined in Shigella flexneri and Klebsiella pneumoniae. Promoters carrying C1 operator sites driving LacZ expression had induction/repression ratios of up to 240-fold in S. flexneri and up to 50-fold in K. pneumoniae. The promoters exhibited remarkably low basal expression, demonstrated modulation by temperature, and showed rapid induction. This system will provide a new opportunity for controlled gene expression in enteric gram-negative bacteria.

Schofield, David A.; Westwater, Caroline; Dolan, Joseph W.; Schmidt, Michael G.; Norris, James S.

2001-01-01

163

Nucleotide sequence of Klebsiella pneumoniae lac genes.  

PubMed Central

The nucleotide sequences of the Klebsiella pneumoniae lacI and lacZ genes and part of the lacY gene were determined, and these genes were located and oriented relative to one another. The K. pneumoniae lac operon is divergent in that the lacI and lacZ genes are oriented head to head, and complementary strands are transcribed. Besides base substitutions, the lacZ genes of K. pneumoniae and Escherichia coli have suffered short distance shifts of reading frame caused by additions or deletions or both during evolutionary divergence from a common ancestral gene. Relative to corresponding E. coli sequences, the nucleotide sequences of the lacZ and lacY genes are 61 and 67% conserved, and the lacI genes are 49% conserved. A comparison of both nucleotide and amino acid sequences revealed that the K. pneumoniae and E. coli lacI genes and lac repressor proteins each are related to the galR gene and gal repressor of E. coli to about the same extent. In terms of evolutionary relationships, the divergence of the forerunner of the galR gene from an ancestral lac repressor gene preceded separation and differentiation of the K. pneumoniae and E. coli lac repressor genes.

Buvinger, W E; Riley, M

1985-01-01

164

Biofilm formation and Klebsiella pneumoniae liver abscess  

PubMed Central

Klebsiella pneumoniae liver abscess is an emerging infectious disease. This syndrome was unknown before the late 1980s when it was first recognized in Taiwan. Over the next two decades it increased in prevalence in Taiwan and was reported from other nations of East Asia. It was then that the rest of the world became aware of this interesting new syndrome. The disease is no longer confined to East Asia, and is now an emerging infection in North America and Europe. How did this come about? We now understand some of the genetic changes that turn commensal E. coli into extra-intestinal pathogens. K pneumoniae is another member of the Enterobacteriaceae that is usually normal flora in the gut, but we know relatively little about how it evolved into an invasive pathogen capable of causing abscesses in normal livers. The phenotype of the liver-invasive strains is hyperviscosity of the polysaccharide capsules, but while the gene that determines that property is required it is not sufficient to create the pathogen, and more research is needed to discover the other virulence genes, and thus to potentially target them therapeutically.

Fierer, Joshua

2012-01-01

165

Enterotoxigenic Klebsiella pneumoniae in acute childhood diarrhoea.  

PubMed

K. pneumoniae strains recovered as pure or predominant isolate from stool specimens of 50 children below three years of age, presenting with acute watery diarrhoea, were studied for heat-labile enterotoxin production. Twenty three (46%) of the 50 crude toxin concentrates showed positivity in rabbit ileal loops and skin permeability tests. Antigenically 17 (34%) and 20 (40%) of the toxin extracts reacted with immuno-purified anti H-LT antibody in latex particle agglutination and immuno-dot blot assays respectively. Polyacrylamide-gel electrophoresis, Western-blotting and enzyme-immunoassay revealed heat-labile enterotoxin and its subunits in 19 (68%) of 28 extracts tested. In 5 of 10 strains tested the toxigenicity could be transferred to recipient Escherichia coli J-35 in plasmid transfer experiments. Klebsiella induced enterotoxigenic diarrhoea and produced a heat-labile toxin which seems to be biologically, antigenically and possibly genetically related to the heat-labile toxin of the cholera-coli family. PMID:1778616

Panigrahi, D; Roy, P; Chakrabarti, A

1991-09-01

166

Mastitis: I. In Vitro Antimicrobial Activity of Alkyl Amines Against Mastitic Bacteria  

Microsoft Academic Search

The activities of branched and straight chain amines (10 to 18 carbons chain length) were compared in inhibiting the growth of five microorganisms that cause about 95% of bovine mastitis. Three gram-positive (Streptococcus aga- lactiae, Streptococcus uberis, Staphylo- coccus aureus) and two gram-negative (Eschericbia coli, Klebsiella pneumoniae) bacteria were used in a trypticase soy broth tube culture growth assay. Sixty-

M. D. Culler; J. Bitman; M. J. Thompson; W. E. Robbins; S. R. Dutky

1979-01-01

167

Murine Monoclonal Antibody Defines a Unique Epitope Shared by Klebsiella Lipopolysaccharides. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

A hybridoma secreting a monoclonal antibody (MAb) directed against Klebsiella lipopolysaccharide (LPS) was derived from spleen cells of mice immunized with a smooth, nonencapsulated Klebsiella strain (Friedlaender 201; serogroup O1). The MAb, called V/9-5...

M. Trautmann K. Vogt C. Hammack A. S. Cross

1994-01-01

168

'KLEBSIELLA' OCCURRENCE, SIGNIFICANCE AND DETECTION IN WATER SYSTEMS: A PROGRESS REPORT  

EPA Science Inventory

Frequent occurrence of Klebsiella in coliform colonization problems found in water supply distribution has prompted the development of a new medium (m-Kleb agar) for specific detection. The medium has excellent differential characteristics, and an average 94% Klebsiella recovery ...

169

Contribution of the Klebsiella pneumoniae Capsule to Bacterial Aggregate and Biofilm Microstructures? †  

PubMed Central

We studied the interaction between capsule production and hydrodynamic growth conditions on the internal and macroscopic structure of biofilms and spontaneously formed aggregates of Klebsiella pneumoniae. Wild-type and capsule-deficient strains were studied as biofilms and under strong and mild hydrodynamic conditions. Internal organization of multicellular structures was determined with a novel image-processing algorithm for feature extraction from high-resolution confocal microscopy. Measures included interbacterial spacing and local angular alignment of individual bacteria. Macroscopic organization was measured via the size distribution of aggregate populations forming under various conditions. Compared with wild-type organisms, unencapsulated mutant organisms formed more organized aggregates with less variability in interbacterial spacing and greater interbacterial angular alignment. Internal aggregate structure was not detectably affected by the severity of hydrodynamic growth conditions. However, hydrodynamic conditions affected both wild-type and mutant aggregate size distributions. Bacteria grown under high-speed shaking conditions (i.e., at Reynolds' numbers beyond the laminar-turbulent transition) formed few multicellular aggregates while clumpy growth was common in bacteria grown under milder conditions. Our results indicate that both capsule and environment contribute to the structure of communities of K. pneumoniae, with capsule exerting influence at an interbacterial length scale and fluid dynamic forces affecting overall particle size.

Dzul, Stephen P.; Thornton, Margaret M.; Hohne, Danial N.; Stewart, Elizabeth J.; Shah, Aayush A.; Bortz, David M.; Solomon, Michael J.; Younger, John G.

2011-01-01

170

Investigation on American cockroaches medically important bacteria in Khorramshahr hospital, Iran  

PubMed Central

Objective To investigate American cockroaches' infection to various bacteria in Khorramshahr Vali-e-Asr hospital, which was done in 2008. Methods In this descriptive cross-sectional study, 20 American cockroaches were caught via direct collection. Medically important bacteria were extracted from their outer surface of bodies by standard procedures. Results Culturing outer surface wash of cockroaches resulted in the separation of Klebsiella, Pseudomonas, Escherichia coli, Staphylococcus, Proteus and Streptococcus. The main common bacteria were Klebsiella (35%) and Pseudomonas (30%). Also, results of culture media showed that about 90% of cockroaches infected to at least one bacterium. Conclusions American cockroaches can transmit pathogenic and potential pathogenic bacteria, therefore their presence in hospitals may be a sanitation challenge. It is recommended to assess plans in purpose to combat these pests in the hospitals.

Kassiri, Hamid; Kassiri, Ali; Kazemi, Shahnaz

2014-01-01

171

Preparation and properties of microencapsulated genetically engineered bacteria cells for oral therapy of uremia  

Microsoft Academic Search

Microencapsulated genetically engineered bacteria cells are a novel approach of oral therapy for uremia. Klebsiella aerogenes urease genes (UreaDABCEFG) are transformed into E. coli DH5? cells through plasmid pKAU17. The transformant can use urea or ammonia as its sole nitrogen source through strain training.\\u000a The urease genetically engineered bacteria cells are entrapped in polyvinyl alcohol (PVA) microcapsules, which can be

Hong Gao; Yaoting Yu; Baoli Cai; Manyan Wang

2004-01-01

172

Klebsiella ozaenae Bacteremia in a Kidney Transplant Recipient  

PubMed Central

Infections remain a dreadful complication after solid organ transplantation. Almost all microorganisms could cause this complication, including unusual ones. We report a 73-year-old patient, with a history of kidney transplant for 38 years on minimum immunosuppression, who presented with high-grade fever and gastrointestinal symptoms. Klebsiella ozaenae was isolated from blood cultures. She had a prompt response to antibiotics and recovered completely in a short period. Subsequent evaluation of her nasal cavity and sinuses did not show any abnormalities. Klebsiella ozaenae is primarily a colonizer of the oral and nasopharyngeal mucosa, which does not usually cause severe infections. Only 12 cases of Klebsiella ozaenae bacteremia have been reported, none of them in the context of solid organ transplant recipient.

Kumar, Shree; Alfaadhel, Talal; AlBugami, Meteb M.

2013-01-01

173

Lectinophagocytosis of encapsulated Klebsiella pneumoniae mediated by surface lectins of guinea pig alveolar macrophages and human monocyte-derived macrophages.  

PubMed Central

Macrophages express a mannose/N-acetylglucosamine-specific lectin which serves as a receptor for nonopsonic phagocytosis of mannose-coated particles. We have examined the binding to guinea pig alveolar macrophages in a serum-free medium of 16 Klebsiella pneumoniae serotypes and of the capsular polysaccharides isolated from 7 of these serotypes. Only five polysaccharides containing the repeating sequence Man alpha 2/3Man or L-Rha alpha 2/3-L-Rha bound to the macrophages. Of the 11 bacterial serotypes expressing such disaccharides in their capsular polysaccharides, 7 bound efficiently, 2 bound poorly, and 2 did not bind at all. No binding occurred with five serotypes lacking these disaccharides. Binding of the bacteria was inhibited by homologous and heterologous capsular polysaccharides that contain the disaccharide sequences, by mannan, and by (Man)25BSA (where BSA is bovine serum albumin). Man alpha 2/3Man-containing oligosaccharides were potent inhibitors compared with monosaccharides. Binding was dependent on Ca2+, modulated by cultivating the macrophages on mannan-coated surfaces, and increased in human monocyte-derived macrophages compared with monocytes. The bulk of the bacteria bound to the macrophages was internalized and killed. The data taken together suggest that Klebsiella pneumoniae cells undergo lectinophagocytosis mediated by capsular disaccharides recognized by the mannose/N-acetylglucosamine-specific lectin of macrophages. This may enhance clearance of the organisms from the serum-poor environment of the lung.

Athamna, A; Ofek, I; Keisari, Y; Markowitz, S; Dutton, G G; Sharon, N

1991-01-01

174

Long-term colonization of spinal cord injury patients with Klebsiella pneumoniae.  

PubMed Central

The duration of colonization of the human perineum, bowel, and urethra with Klebsiella pneumoniae was studied in 10 male patients with spinal cord injury while they were undergoing rehabilitation in the hospital. Colonization defined as persistence of klebsiellae of the same serotype occurred on 13 occasions in five of the patients for up to 55 days. Colonization was less marked with Klebsiella than with Pseudomonas spp. The presence of quadriplegia correlated with Klebsiella colonization and also with the presence of positive Klebsiella cultures from the urethra and perineum. Seven episodes of significant bacteriuria occurred with or after the finding of positive cultures from body sites.

Montgomerie, J Z; Gilmore, D S; Ashley, M A; Schick, D G; Jimenez, E M

1989-01-01

175

Defective cellular immunity to gram-negative bacteria in cystic fibrosis patients.  

PubMed Central

In vitro lymphocyte responses to Pseudomonas aeruginosa have been found to be impaired in cystic fibrosis patients with advanced clinical disease. The responses to Klebsiella pneumoniae, Serratia marcescens, and Proteus mirabilis were studied in a similar group of cystic fibrosis patients and normal individuals. Cystic fibrosis patients found to be unresponsive to pseudomonas were also unresponsive to klebsiella, serratia, and proteus. Responsiveness to Staphylococcus aureus was not impaired in cystic fibrosis patients. We postulate that in vitro lymphocyte responses to several gram-negative bacteria require the function of a lymphocyte subpopulation which may be impaired in some cystic fibrosis patients.

Sorensen, R U; Stern, R C; Chase, P; Polmar, S H

1979-01-01

176

Differentiation of Enterobacter aerogenes from Klebsiellae by Deoxyribonucleic Acid Reassociation  

Microsoft Academic Search

Polynucleotide sequence relatedness tests were carried out to determine the extent of deoxyribonucleic acid (DNA) divergence among species of Klebsiella and Enterobacter aerogenes strains. Labeled, denatured DNA fragments from K. pneumoniae type 2 and E. aerogenes 1627-66 were each incubated with an excess of unlabeled DNA fragments from Klebsielia species and strains of E. aerogenes. Reassociated DNA duplexes were separated

DON J. BRENNER; A. G. STEIGERWALT; G. R. FANNING

1972-01-01

177

Neonatal Sepsis due to Klebsiella: Frequency, Outcome and Antibiotic Sensitivity  

Microsoft Academic Search

Sepsis is a significant cause of morbidity and mortality in neonates. The most common pathogens of bacterial sepsis and antibiotic sensitivity patterns vary in different parts of the world. The aim of this study was to determine the most common pathogens and outcome of neonatal sepsis and also antibiotic sensitivity patterns of Klebsiella species. A retrospective descriptive study was carried

E Malakan Rad

178

Klebsiella pneumoniae Antimicrobial Drug Resistance, United States, 1998-2010  

PubMed Central

We studied antimicrobial-resistant Klebsiella pneumoniae for 1998–2010 by using data from The Surveillance Network. Susceptibility results (n = 3,132,354) demonstrated significant increases in resistance to all antimicrobial drugs studied, except tetracycline. Cross-resistance among carbapenem-resistant K. pneumoniae was lower for tetracycline and amikacin.

Sanchez, Guillermo V.; Master, Ronald N.; Clark, Richard B.; Fyyaz, Madiha; Duvvuri, Padmaraj; Ekta, Gupta

2013-01-01

179

Order of genes near nif in Klebsiella pneumoniae.  

PubMed

Analysis of strains with deletions of all or part of nif have ordered the Klebsiella pneumoniae genetic loci as thi rbt dal udk gnd rfb has nif shiA. The his-nif plasmids pRD1 and pTM4010 contain the genes gnd rfb his nif shiA. PMID:378930

MacNeil, D; Supiano, M A; Brill, W J

1979-06-01

180

Genome Sequence of Klebsiella pneumoniae Urinary Tract Isolate Top52  

PubMed Central

Klebsiella pneumoniae is a significant cause of nosocomial infections, including ventilator-associated pneumonias and catheter-associated urinary tract infections. K. pneumoniae strain TOP52 #1721 (Top52) was isolated from a woman presenting with acute cystitis and subsequently characterized using various murine models of infection. Here we present the genome sequence of K. pneumoniae Top52.

Johnson, Jeremiah G.; Spurbeck, Rachel R.; Sandhu, Sukhinder K.

2014-01-01

181

Capsular typing of klebsiellae by coagglutination and latex agglutination.  

PubMed

A simple method for capsular serotype determination of Klebsiella is described, using staphylococci or latex particles coated by specific antibodies and the supernatant of a bacterial suspension in saline as antigen. These methods may be at least as reliable as other methods and easier to perform and less expensive than other methods. PMID:7014611

Onokodi, J K; Wauters, G

1981-04-01

182

Laryngeal Scleroma Associated with Klebsiella pneumoniae subsp. ozaenae  

PubMed Central

Klebsiella pneumoniae subsp. ozaenae was isolated from the pharynx of a woman with laryngeal scleroma. K. pneumoniae subsp. ozaenae is rarely isolated from clinical infections and has never been reported in laryngeal scleroma, which is usually caused by K. pneumoniae subsp. rhinoscleromatis.

De Champs, C.; Vellin, J. F.; Diancourt, L.; Brisse, S.; Kemeny, J. L.; Gilain, L.; Mom, T.

2005-01-01

183

Structural investigation of Klebsiella serotype K10 capsular polysaccharide.  

PubMed

The primary structure of Klebsiella serotype K10 capsular polysaccharide has been investigated using mainly the techniques of methylation, partial hydrolysis, and 1H and 13C NMR spectroscopy. The polysaccharide was found to consist of hexasaccharide repeating units having the following structure: (formula; see text) PMID:3830182

Chakrabarti, A; Chakraborty, A K

1987-04-01

184

SitA contributes to the virulence of Klebsiella pneumoniae in a mouse infection model.  

PubMed

Klebsiella pneumoniae is an opportunistic pathogen, which causes a wide range of nosocomial infections. Recently, antibiotic resistance makes K. pneumoniae infection difficult to deal with. Investigation on virulence determinants of K. pneumoniae can provide more information about pathogenesis and unveil new targets for treatment or vaccine development. In this study, SitA, a Fur-regulated divalent cation transporter, was found significantly increased when K. pneumoniae was cultured in a nutrient-limited condition. A sitA-deletion strain (?sitA) was created to characterize the importance of SitA in virulence. ?sitA showed higher sensitivity toward hydroperoxide than its parental strain. In a mouse intraperitoneal infection model, the survival rate of mice infected with ?sitA strain increased greatly when compared with that of mice infected with the parental strain, suggesting that sitA deletion attenuates the bacterial virulence in vivo. To test whether ?sitA strain is a potential vaccine candidate, mice were immunized with inactivated bacteria and then challenged with the wild-type strain. The results showed that using ?sitA mutant protected mice better than using the wild-type strain or the capsule-negative congenic bacteria. In summary, SitA was found being important for the growth of K. pneumoniae in vivo and deleting sitA might be a potential approach to generate vaccines against K. pneumoniae. PMID:24211873

Sun, Wei-Sheng W; Syu, Wan-Jr; Ho, Wen-Li; Lin, Ching-Nan; Tsai, Shih-Feng; Wang, Shao-Hung

2014-02-01

185

Susceptibility of different phases of biofilm of Klebsiella pneumoniae to three different antibiotics.  

PubMed

The existence of majority of bacteria in biofilm mode makes it difficult to eradicate them as antibiotics at much higher concentrations than the MICs are required to destroy these bacteria. This study investigated the effect of different classes of antibiotics on different phases of biofilm formed by Klebsiella pneumoniae. The organism was grown in different phases relevant to biofilm formation: planktonic cells at mid-log phase, planktonic cells at stationary phase, adherent monolayers and mature biofilms and their susceptibility to different classes of antibiotics was assessed. The results showed that planktonic organisms were susceptible to ciprofloxacin, amikacin and piperacillin, and their MBC values were same or eight times higher than their corresponding MICs. MBC of ciprofloxacin and amikacin was found to be four and eight times higher for monolayer than planktonic cells. On the other hand, MBC of piperacillin was >1024??g?ml(-1). K. pneumoniae in a biofilm growth mode was more resistant to antibiotics than all other modes. The effect of amikacin and ciprofloxacin on young and older biofilms, at the highest achievable serum concentrations, was also examined. It was observed that amikacin at a concentration of 40??g?ml(-1) was able to eradicate the young biofilms; however, with increase in the age of the biofilm, it became completely ineffective. Calcofluor staining suggested increased production of exopolysaccharide in older biofilm compared with younger biofim that might be responsible for the increased resistance of older biofilm of K. pneumoniae to antibiotics. PMID:23168403

Singla, Saloni; Harjai, Kusum; Chhibber, Sanjay

2013-02-01

186

Invasion of cultured human epithelial cells by Klebsiella pneumoniae isolated from the urinary tract.  

PubMed

The mechanisms which enable entry into cultured human epithelial cells by Klebsiella pneumoniae were compared with those of Salmonella typhi Ty2. K. pneumoniae 3091, isolated from a urine sample of a patient with a urinary tract infection, invaded human epithelial cells from the bladder and ileocecum and persisted for days in vitro. Electron microscopic studies demonstrated that K. pneumoniae was always contained in endosomes. The internalization mechanism(s) triggered by K. pneumoniae was studied by invasion assays conducted with different inhibitors that act on prokaryotic and eukaryotic cell structures and processes. Chloramphenicol inhibition of bacterial uptake revealed that bacterial de novo protein synthesis was essential for efficient invasion by K. pneumoniae and S. typhi. Interference with receptor-mediated endocytosis by g-strophanthin or monodansylcadaverine and inhibition of endosome acidification by monensin reduced the number of viable intracellular K. pneumoniae cells, but not S. typhi cells. The depolymerization of microfilaments by cytochalasin D inhibited the uptake of both bacteria. Microtubule depolymerization caused by colchicine, demecolcine, or nocodazole and the stabilization of microtubules with taxol reduced only the invasion ability of K. pneumoniae. S. typhi invasion was unaffected by microtubule depolymerization or stabilization. These data suggest that the internalization mechanism triggered by K. pneumoniae 3091 is strikingly different from the solely microfilament-dependent invasion mechanism exhibited by many of the well-studied enteric bacteria, such as enteroinvasive Escherichia coli, Salmonella, Shigella, and Yersinia strains. PMID:9199471

Oelschlaeger, T A; Tall, B D

1997-07-01

187

Two cases of monomicrobial intraabdominal abscesses due to KPC - 3 Klebsiella pneumoniae ST258 clone  

PubMed Central

Background Knowledge of the etiology of pyogenic liver and pancreatic abscesses is an important factor in determining the success of combined surgical and antibiotic treatment. Literature shows geographical variations in the prevalence and distribution of causative organisms, and the spread of Klebsiella pneumoniae carbapenemase-producing bacteria is an emerging cause of abdominal infections. Case presentation We herein describe two cases of intra-abdominal abscesses due to monomicrobial infection by Klebsiella pneumoniae Sequence Type 258 producing K. pneumoniae carbapenemase 3 (KPC-Kp). In case 1, a 50-year-old HIV-negative Italian woman with chronic pancreatitis showed infection of a pancreatic pseudocystic lesion caused by KPC-Kp. In case 2, a 64-year-old HIV- negative Italian woman with pancreatic neoplasm and liver metastases developed a liver abscess due to KPC after surgery. Both women were admitted to our hospital but to different surgical units. The clonal relationship between the two isolates was investigated by pulsed-field gel electrophoresis (PFGE). In case 2, the patient was already colonized at admission and inter-hospital transmission of the pathogen was presumed. A long-term combination regimen of colistin with tigecycline and percutaneous drainage resulted in full recovery and clearance of the multidrug-resistant (MDR) pathogen. Conclusions Timely microbiological diagnosis, the combined use of new and old antibiotics and radiological intervention appeared to be valuable in managing these serious conditions. The emergence and dissemination of MDR organisms is posing an increasing challenge for physicians to develop new therapeutic strategies and control and prevention frameworks.

2011-01-01

188

Absence of Escherichia coli, Listeria monocytogenes, and Klebsiella pneumoniae antigens within inflammatory bowel disease tissues.  

PubMed Central

BACKGROUND: Escherichia coli, listeria, and streptococcal antigens have been found in Crohn's disease tissues. Antibodies to Klebsiella pneumoniae have been found in patients with inflammatory bowel disease and ankylosing spondylitis. The presence of these bacterial antigens in Crohn's granulomas would be of aetiological interest, while their presence in ulcers alone would be more likely to indicate secondary infection. AIM: To investigate inflammatory bowel disease tissues for the presence of these bacteria. METHODS: Formalin fixed, paraffin processed sections from 53 patients (19 ulcerative colitis, 23 Crohn's disease; 11 normal tissues from cancer resections) were studied by immunohistochemistry. Control tissue consisted of normal human small bowel injected submucosally with either E coli, Listeria monocytogenes, Proteus mirabilis, or Klebsiella pneumoniae serotypes K2, 3, 17, 21, 26, 36, and 50, and colonic biopsies from a child with E coli 0114 infection. Tissues were stained by Gram-Twort, and with specific antibodies for E coli (Dako B357), L monocytogenes (Difco 2302-50), and K pneumoniae (Biogenesis 5580-5208) using an immunoperoxidase technique. RESULTS: Positive staining for E coli was observed on the luminal surface epithelium and in ulcers in 35% of Crohn's disease patients, 26% of ulcerative colitis patients, and no normal controls. Superficial staining for L monocytogenes was observed in one case of ulcerative colitis only. Staining for K pneumoniae was observed in one case of ulcerative colitis and one of Crohn's disease. No granulomas, giant cells, or germinal centres stained positively for any of the three bacterial antigens. CONCLUSIONS: These data do not support a primary role for E coli, L monocytogenes, and K pneumoniae in inflammatory bowel disease. The presence of E coli antigens in ulcers suggests secondary infection in these lesions. Images

Walmsley, R S; Anthony, A; Sim, R; Pounder, R E; Wakefield, A J

1998-01-01

189

Rapid ertapenem susceptibility testing and Klebsiella pneumoniae carbapenemase phenotype detection in Klebsiella pneumoniae isolates by use of automated microscopy of immobilized live bacterial cells.  

PubMed

We evaluated detection of ertapenem (ETP) resistance and Klebsiella pneumoniae carbapenemase (KPC) in 47 Klebsiella pneumoniae isolates using a novel automated microscopy system. Automated microscopy correctly classified 22/23 isolates as ETP resistant and 24/24 as ETP susceptible and correctly classified 21/21 isolates as KPC positive and 26/26 as KPC negative. PMID:24391202

Burnham, Carey-Ann D; Frobel, Rachel A; Herrera, Monica L; Wickes, Brian L

2014-03-01

190

Bacteria bites  

NASA Astrophysics Data System (ADS)

Naturally occurring bacteria may be a future solution for myriad pollution problems, mounting laboratory evidence suggests. Last month, USGS scientists reported in Nature that microbes living in oxygen-free sediments can break down derivatives of hydrofluorocarbons, which are among the compounds under consideration to replace ozone-destroying chlorofluorocarbons (CFCs). And now, another USGS scientist reports in the July 14 Nature that microbes which degrade toxic and carcinogenic aromatic hydrocarbons like benzene and toluene can be boosted with an iron additive or chemical binder to work in anaerobic conditions that are commonly found in heavily polluted aquifers. Previously, scientists thought the bacteria could reduce the hard pollutants only if plenty of dissolved oxygen was in the water. Other bacteria have been shown to convert uranium to a highly insoluble form in cbntaminated waters as well.

191

The structure of Klebsiella serotype II capsular polysaccharide.  

PubMed

Using periodate oxidation, methylation analysis, the characterization of oligosaccharides obtained by partial acid hydrolysis, p.m.r. spectroscopy, and analytical ultracentrifugation, the structure of the (mildly alkali-treated) Klebsiella serotype 11 capusular polysaccharide has been elucidated. The tetrasaccharide repeating-unit comprises the sequence yields 3)-beta-D-Glcp-(1 yields 3)-beta-D-GlcUAp-(1 yields 3)-alpha-D-Galp-(1 yields with a 4,6-O-(1-carboxyethylidene)-alpha-D-galactosyl residue linked to O-4 of the glucuronic acid residue. The structural basis for some serological cross-reactions of the Klebseilla K11 antigen is discussed, and it is shown that rabbit antisera against the Klebsiella K11 test-strain predominantly contain K agglutinins specific for branch-terminal 4,6-O-(1-carboxyethylidene)-D-galactose. PMID:236829

Thurow, H; Choy, Y M; Frank, N; Niemann, H; Stirm, S

1975-05-01

192

Structure of the capsular polysaccharide of Klebsiella serotype K74.  

PubMed

The capsular polysaccharide of Klebsiella serotype K74 belongs to a chemogroup consisting of seven strains, of which four contain 1-carboxyethylidene groups (pyruvic acid acetals). The polysaccharide from K74 is demonstrated to be of the "3 + 2" type, and to be based on the repeating unit shown (Formula, see text). The capsular polysaccharide from Klebsiella K74 is composed of D-glucuronic acid, D-galactose, and D-mannose, and this chemotype includes a total of seven strains, of which four have 1-carboxyethylidene groups (pyruvic acid acetals). In this chemogroup, the structures of the capsular polysaccharides of the serotypes K20 (ref. 3) and K21 (ref. 4) have been published. PMID:7438137

Dutton, G S; Paulin, M

1980-12-01

193

Isolation and characterization of Klebsiella pneumoniae unencapsulated mutants  

SciTech Connect

Klebsiella pneumoniae mutants were obtained after UV irradiation and negative selection with anticapsular serum. Unencapsulation, rather than expression of a structurally altered capsule, was found in the mutants. The mutant strains showed no alterations in their outer membrane proteins and lipopolysaccharide, and a great similarity with the wild type in the properties tested (serum resistance, antimicrobial sensitivity, and lipopolysaccharide-specific bacteriophage sensitivity), with the exception of a higher cell surface hydrophobicity and resistance to bacteriophage FC3-9.

Benedi, V.J.; Ciurana, B.; Tomas, J.M.

1989-01-01

194

Complementation analysis of Klebsiella pneumoniae mutants defective in nitrogen fixation  

Microsoft Academic Search

A series of mutants defective in nitrogen fixation (nif) were isolated in Klebsiella pneunoniae strain M5a1. The nif mutations were either located on plasmid pRD1 or on the K. pneumoniae chromosome. A total of 37 plasmid mutants and 28 chromosomal mutants were employed in complementation tests using the acetylene reduction technique. Most mutants could be assigned to one of seven

Ray Dixon; Christina Kennedy; Adám Kondorosi; Viji Krishnapillai; Mike Merrick

1977-01-01

195

Limiting and controlling carbapenem-resistant Klebsiella pneumoniae  

PubMed Central

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is resistant to almost all antimicrobial agents, is associated with substantial morbidity and mortality, and poses a serious threat to public health. The ongoing worldwide spread of this pathogen emphasizes the need for immediate intervention. This article reviews the global spread and risk factors for CRKP colonization/infection, and provides an overview of the strategy to combat CRKP dissemination.

Saidel-Odes, Lisa; Borer, Abraham

2014-01-01

196

Enhanced 2,3-butanediol production by Klebsiella pneumoniae SDM  

Microsoft Academic Search

Enhanced 2,3-butanediol (BD) production was carried out by Klebsiella pneumoniae SDM. The nutritional requirements for BD production by K. pneumoniae SDM were optimized statistically in shake flask fermentations. Corn steep liquor powder and (NH4)2HPO4 were identified as the most significant factors by the two-level Plackett–Burman design. Steepest ascent experiments were\\u000a applied to approach the optimal region of the two factors

Cuiqing Ma; Ailong Wang; Jiayang Qin; Lixiang Li; Xulu Ai; Tianyi Jiang; Hongzhi Tang; Ping Xu

2009-01-01

197

Structure of the capsular polysaccharide of Klebsiella serotype K79.  

PubMed

The structure of the capsular polysaccharide from Klebsiella K79 was determined by the techniques of methylation, periodate oxidation, beta-elimination, chromic acid oxidation, and partial hydrolysis. N.m.r. spectroscopy (1H and 13C) was used extensively to establish the nature of the anomeric linkages of the polysaccharide and of oligosaccharides derived through degradative procedures. The polysaccharide was found to have the heptasaccharide, "5 + 2" repeating unit: (Formula: see text). PMID:4092207

Dutton, G G; Lim, A V

1985-12-01

198

Structural investigation of Klebsiella serotype K70 polysaccharide.  

PubMed

By using the techniques of methylation analysis, uronic acid degradation, partial hydrolysis, and periodate oxidation, th structure of the capsular polysaccharide from Klebsiella serotype K70 has been investigated. Nuclear magnetic resonance was used extensively to characterize fragments obtained as a result of the various degradation procedures. The existence of a linear, hexasaccharide repeating unit having a 1-carboxyethylidene group attached to a 2-linked alpha-L-rhamnosyl residue in every second repeating unit has been demonstrated. PMID:667876

Dutton, G G; Mackie, K L

1978-05-01

199

Structural investigation of Klebsiella serotype K36 polysaccharide.  

PubMed

Klebsiella D36 capsular polysaccharide has been investigated by methylation, Smith-periodate oxidation and partial hydrolysis techniques. The structure was found to consist of a hexasaccharide repeating unit as shown. The anomeric configurations of the sugar residues were determined by 1H and 13Cn.m.r.spectroscopy on isolated oligomers obtained during the degradative studies and on the intact polysaccharide. PMID:193645

Dutton, G G; Mackie, K L

1977-05-01

200

Significance of Circulating Capsular Antigen in Klebsiella Infections  

PubMed Central

Klebsiella capsular antigen (KCA) was detected in serum by counterimmunoelectrophoresis in 8 of 31 patients with klebsiella bacteremia, in two nonbacteremic patients with pneumonia and meningitis, respectively, and in the cerebrospinal fluid only of 1 of the 31 bacteremic patients. It was also detected in cerebrospinal fluid, urine (two patients each) empyema fluid, and abscess drainage (one patient each). Patients whose bacteremias were associated with a discernible tissue focus (e.g., pneumonia) tended to have detectable serum KCA more often than those with “primary bacteremia.” A fatal outcome occurred in six of nine bacteremia patients with detectable serum KCA compared with 4 of 22 without demonstrable antigen (P < 0.05). Persistent antigenemia and antigenuria aided in the diagnosis of perinephric abscess in one patient, and increasing levels of serum KCA anticipated treatment failure in another patient with pneumonia. The presence of detectable KCA in the serum of patients infected with klebsiella thus appeared to correlate with severity of infection, with persistence of active foci, and with a poorer prognosis than in those patients who had no detectable antigen. Whether the presence of this antigen itself plays any pathogenic role needs to be further clarified. Images

Pollack, Matthew

1976-01-01

201

Inhibition of Shigella flexneri by the normal intestinal flora. I. Mechanisms of inhibition by Klebsiella.  

PubMed

Growth curves were plotted for Shigella flexneri and Klebsiella (Aerobacter aerogenes) multiplying in pure and mixed culture. In mixed culture, Klebsiella inhibited Shigella. Exponential growth was interrupted and Shigella entered into a logarithmic death phase. An analysis of cultures at the time inhibition occurred revealed that formic and acetic acids produced by Klebsiella were responsible for the inhibition of Shigella. Klebsiella strongly reduced the culture medium. The volatile fatty acids, operating under reduced conditions, exerted a bactericidal effect on Shigella. Results are discussed with reference to the possible role of volatile fatty acids as factors responsible for Shigella inhibition in vivo. PMID:6032512

Hentges, D J

1967-04-01

202

Food as a source of Klebsiella species for colonisation and infection of intensive care patients.  

PubMed Central

Food prepared for intensive care patients was frequently contaminated with Klebsiella species. Sixty-eight per cent of nasogastric feeds were contaminated with up to 10(4) klebsiellae per ml. Hospital kitchens were the source of contamination. Three patients ingested klebsiellae and subsequently excreted the same serotype in their faeces. Over a four-week period there was a correlation between kitchen, food, faecal, and clinical serotypes of klebsiellae. Serotypes ingested by intensive care patients occurred more frequently in clinical isolates from intensive care patients than from other hospital patients. Patients often acquired a food strain that had been ingested by another patient on the same ward.

Casewell, M; Phillips, I

1978-01-01

203

Tolerance of anaerobic bacteria to chlorinated solvents.  

PubMed

The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation. PMID:24441515

Koenig, Joanna C; Groissmeier, Kathrin D; Manefield, Mike J

2014-01-01

204

Tolerance of Anaerobic Bacteria to Chlorinated Solvents  

PubMed Central

The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation.

Koenig, Joanna C.; Groissmeier, Kathrin D.; Manefield, Mike J.

2014-01-01

205

Endocarditis Due to Rare and Fastidious Bacteria  

PubMed Central

The etiologic diagnosis of infective endocarditis is easily made in the presence of continuous bacteremia with gram-positive cocci. However, the blood culture may contain a bacterium rarely associated with endocarditis, such as Lactobacillus spp., Klebsiella spp., or nontoxigenic Corynebacterium, Salmonella, Gemella, Campylobacter, Aeromonas, Yersinia, Nocardia, Pasteurella, Listeria, or Erysipelothrix spp., that requires further investigation to establish the relationship with endocarditis, or the blood culture may be uninformative despite a supportive clinical evaluation. In the latter case, the etiologic agents are either fastidious extracellular or intracellular bacteria. Fastidious extracellular bacteria such as Abiotrophia, HACEK group bacteria, Clostridium, Brucella, Legionella, Mycobacterium, and Bartonella spp. need supplemented media, prolonged incubation time, and special culture conditions. Intracellular bacteria such as Coxiella burnetii cannot be isolated routinely. The two most prevalent etiologic agents of culture-negative endocarditis are C. burnetti and Bartonella spp. Their diagnosis is usually carried out serologically. A systemic pathologic examination of excised heart valves including periodic acid-Schiff (PAS) staining and molecular methods has allowed the identification of Whipple's bacillus endocarditis. Pathologic examination of the valve using special staining, such as Warthin-Starry, Gimenez, and PAS, and broad-spectrum PCR should be performed systematically when no etiologic diagnosis is evident through routine laboratory evaluation.

Brouqui, P.; Raoult, D.

2001-01-01

206

Ankylosing spondylitis, HLA-B27, and Klebsiella: a study of lymphocyte reactivity of anti-Klebsiella sera.  

PubMed Central

Twenty three anti-Klebsiella antisera were tested for their cytotoxic activity and four for their binding capacity for peripheral blood lymphocytes (PBL) from patients with HLA-B27 positive ankylosing spondylitis (AS+B27+) and from B27 positive (AS-B27+) and B27 negative (AS-B27-) healthy individuals. None of the antisera showed specific activity against PBL from any particular group. The antisera tested included two anti-Klebsiella K43 sera provided by an Australian group, who have reported them to be specifically cytotoxic for AS+B27+ PBL, four antisera raised against a Klebsiella K43 strain provided by this group, and an antiserum from another group, who have reported it as having increased binding capacity for AS+B27+ and AS-B27+ PBL compared with AS-B27- PBL. The results of other workers who have attempted to reproduce the results of either group are reviewed and the possible reasons for the repeated failure to confirm the reported findings are discussed.

Singh, B; Milton, J D; Woodrow, J C

1986-01-01

207

Bacteria Counter  

NASA Technical Reports Server (NTRS)

Science Applications, Inc.'s ATP Photometer makes a rapid and accurate count of the bacteria in a body fluid sample. Instrument provides information on the presence and quantity of bacteria by measuring the amount of light emitted by the reaction between two substances. Substances are ATP adenosine triphosphate and luciferase. The reactants are applied to a human body sample and the ATP Photometer observes the intensity of the light emitted displaying its findings in a numerical output. Total time lapse is usually less than 10 minutes, which represents a significant time savings in comparison of other techniques. Other applications are measuring organisms in fresh and ocean waters, determining bacterial contamination of foodstuffs, biological process control in the beverage industry, and in assay of activated sewage sludge.

1981-01-01

208

Antibiofilm efficacy of silver nanoparticles against biofilm of extended spectrum ?-lactamase isolates of Escherichia coli and Klebsiella pneumoniae  

NASA Astrophysics Data System (ADS)

The ability of bacteria to develop antibiotic resistance and colonize abiotic surfaces by forming biofilms is a major cause of medical implant-associated infections and results in prolonged hospitalization periods and patient mortality. Different approaches have been used for preventing biofilm-related infections in health care settings. Many of these methods have their own demerits that include chemical-based complications; emergent antibiotic-resistant strains, and so on. Silver nanoparticles (AgNPs) are renowned for their influential antimicrobial activity. We demonstrate the biofilm formation by extended spectrum ?-lactamases-producing Escherichia coli and Klebsiella spp. by direct visualization applying tissue culture plate, tube, and Congo red agar methods. Double fluorescent staining for confocal laser scanning microscopy (CLSM) consisted of propidium iodide staining to detect bacterial cells and concanavalin A-fluorescein isothiocyanate staining to detect the exopolysaccharides matrix were used. Scanning electron microscopy observations clearly indicate that AgNPs reduced the surface coverage by E. coli and Klebsiella spp. thus prevent the biofilm formations. Double-staining technique using CLSM provides the visual evidence that AgNPs arrested the bacterial growth and prevent the exopolysaccharides formation. The AgNPs-coated surfaces effectively restricted biofilm formation of the tested bacteria. In our study, we could demonstrate the complete antibiofilm activity AgNPs at a concentration as low as 50 ?g/ml. Our findings suggested that AgNPs can be exploited towards the development of potential antibacterial coatings for various biomedical and environmental applications. These formulations can be used for the treatment of drug-resistant bacterial infections caused by biofilms, at much lower nanosilver loading with higher efficiency.

Ansari, Mohammad Azam; Khan, Haris M.; Khan, Aijaz A.; Cameotra, Swaranjit Singh; Pal, Ruchita

2013-09-01

209

Overproduction of the secretin OutD suppresses the secretion defect of an Erwinia chrysanthemi outB mutant  

Microsoft Academic Search

OutB is a component of the Erwinia chrysanthemi Out secretion machinery. Homologues of OutB have been described in two other bacteria, Klebsiella oxytoca and Aeromonas hydrophila, but their requirement in the secretion process seems to be different. Study of OutB topology with the BlaM topology probe suggests that it is an inner-membrane protein with a large periplasmic domain. However, fractionation

Guy Condemine; Vladimir E. Shevchik

2000-01-01

210

Genetic Characterization and Emergence of the Metallo-?-Lactamase GIM-1 in Pseudomonas spp. and Enterobacteriaceae during a Long-Term Outbreak  

PubMed Central

Since the first isolation in 2002, the metallo-?-lactamase GIM-1 has not been detected outside Germany. The data presented here, for 50 clinical blaGIM-1-positive isolates, including Pseudomonas spp. and Enterobacteriaceae (Enterobacter cloacae, Klebsiella oxytoca, Serratia marcescens, Escherichia coli, and Citrobacter freundii), collected between 2007 and 2012 at the original site in an ongoing outbreak, demonstrate a diverse genetic background and dissemination of the gene conferring resistance to enteric bacteria.

Brodner, Alexander H. B.; Wydra, Stephan; Ressina, Sofija; Henrich, Birgit; Pfeffer, Klaus; Toleman, Mark A.; MacKenzie, Colin R.

2013-01-01

211

Decolorization of synthetic melanoidins-containing wastewater by a bacterial consortium  

Microsoft Academic Search

The presence of melanoidins in molasses wastewater leads to water pollution both due to its dark brown color and its COD contents.\\u000a In this study, a bacterial consortium isolated from waterfall sediment was tested for its decolorization. The identification\\u000a of culturable bacteria by 16S rDNA based approach showed that the consortium composed of Klebsiella oxytoca, Serratia mercescens, Citrobacter sp. and

Suhuttaya Jiranuntipon; Supat Chareonpornwattana; Somsak Damronglerd; Claire Albasi; Marie-Line Delia

2008-01-01

212

The Prevalence of TEM and SHV Genes among Extended-Spectrum Beta-Lactamases Producing Escherichia Coli and Klebsiella Pneumoniae  

PubMed Central

Objective(s) Production of extended-spectrum beta-lactamases (ESBLs) by enteric bacteria continues to be a major problem in hospitals and community. ESBLs producing bacteria cause many serious infections including urinary tract infections, peritonitis, cholangitis and intra-abdominal abscess. The aim of this study was to determine the prevalence of ESBLs producing Escherichia coli and Klebsiella pneumoniae bacteria isolated from clinical samples of patients attending Imam Reza and Ghaem University Hospitals, Mashhad, Northeast of Iran. Materials and Methods During 2009 and 2010, 82 strains of E. coli and 78 strains of K. pneumoniae were isolated from out-patients and hospitalized patients and they were examined by Oxoid combination disk test and PCR methods. Results We found that 43.9% of E. coli and 56.1% of K. pneumoniae produced ESBLs. The frequency of SHV and TEM among the ESBLs producing isolates were 14.4% and 20.6%, respectively. Ratios of ESBLs positive isolates from out-patients to hospitalized patients were 24/33. Conclusion This study shows that the prevalence of ESBLs producing E. coli and K. pneumoniae is high in both study groups (out-patients and hospitalized patients). Therefore it seems that continuous surveillance is essential to monitor the ESBLs producing microorganisms in hospitals and community.

Zaniani, Fatemeh Riyahi; Meshkat, Zahra; Naderi Nasab, Mahboubeh; Khaje-Karamadini, Mehrangiz; Ghazvini, Kiarash; Rezaee, Abdolrahim; Esmaily, Habibollah; Nabavinia, Maryam Sadat; Darban Hoseini, Mahboubeh

2012-01-01

213

Biofilm formation of Klebsiella pneumoniae on urethral catheters requires either type 1 or type 3 fimbriae  

PubMed Central

Urinary catheters are standard medical devices utilized in both hospital and nursing home settings, but are associated with a high frequency of catheter-associated urinary tract infections (CAUTI). In particular, biofilm formation on the catheter surface by uropathogens such as Klebsiella pneumoniae causes severe problems. Here we demonstrate that type 1 and type 3 fimbriae expressed by K. pneumoniae enhance biofilm formation on urinary catheters in a catheterized bladder model that mirrors the physico-chemical conditions present in catheterized patients. Furthermore, we show that both fimbrial types are able to functionally compensate for each other during biofilm formation on urinary catheters. In situ monitoring of fimbrial expression revealed that neither of the two fimbrial types is expressed when cells are grown planktonically. Interestingly, during biofilm formation on catheters, both fimbrial types are expressed, suggesting that they are both important in promoting biofilm formation on catheters. Additionally, transformed into and expressed by a nonfimbriated Escherichia coli strain, both fimbrial types significantly increased biofilm formation on catheters compared with the wild-type E. coli strain. The widespread occurrence of the two fimbrial types in different species of pathogenic bacteria stresses the need for further assessment of their role during urinary tract infections.

Stahlhut, Steen G; Struve, Carsten; Krogfelt, Karen A; Reisner, Andreas

2012-01-01

214

Molecular dissection of the evolution of carbapenem-resistant multilocus sequence type 258 Klebsiella pneumoniae  

PubMed Central

Infections caused by drug-resistant bacteria are a major problem worldwide. Carbapenem-resistant Klebsiella pneumoniae, most notably isolates classified as multilocus sequence type (ST) 258, have emerged as an important cause of hospital deaths. ST258 isolates are predominantly multidrug resistant, and therefore infections caused by them are difficult to treat. It is not known why the ST258 lineage is the most prevalent cause of multidrug-resistant K. pneumoniae infections in the United States and other countries. Here we tested the hypothesis that carbapenem-resistant ST258 K. pneumoniae is a single genetic clone that has disseminated worldwide. We sequenced to closure the genomes of two ST258 clinical isolates and used these genomes as references for comparative genome sequencing of 83 additional clinical isolates recovered from patients at diverse geographic locations worldwide. Phylogenetic analysis of the SNPs in the core genome of these isolates revealed that ST258 K. pneumoniae organisms are two distinct genetic clades. This unexpected finding disproves the single-clone hypothesis. Notably, genetic differentiation between the two clades results from an ?215-kb region of divergence that includes genes involved in capsule polysaccharide biosynthesis. The region of divergence appears to be a hotspot for DNA recombination events, and we suggest that this region has contributed to the success of ST258 K. pneumoniae. Our findings will accelerate research on novel diagnostic, therapeutic, and vaccine strategies designed to prevent and/or treat infections caused by multidrug resistant K. pneumoniae.

DeLeo, Frank R.; Chen, Liang; Porcella, Stephen F.; Martens, Craig A.; Kobayashi, Scott D.; Porter, Adeline R.; Chavda, Kalyan D.; Jacobs, Michael R.; Mathema, Barun; Olsen, Randall J.; Bonomo, Robert A.; Musser, James M.; Kreiswirth, Barry N.

2014-01-01

215

Therapeutic activities of cefazolin, cefotaxime, and ceftazidime against experimentally induced Klebsiella pneumoniae pneumonia in rats.  

PubMed Central

The efficacies of several dosage schedules of cefazolin, cefotaxime, and ceftazidime, started 12 or 36 h after infection, were examined in experimental pneumonia caused by Klebsiella pneumoniae in rats. The therapeutic activities of the cephalosporins were compared with the antibacterial activities in vitro and the serum concentration curves. The course of experimental pneumonia was rapid and characterized by tissue necrosis. Response to antimicrobial treatment was evaluated with respect to mortality and numbers of bacteria in lung (left lobe), blood, and pleural fluid. When antibiotic treatment was started early, i.e., 12 h after bacterial inoculation, cefotaxime and ceftazidime were equally effective and superior to cefazolin. Eleven doses of 10 mg of cefotaxime or ceftazidime per kg or 11 doses of 60 mg of cefazolin per kg were required to improve the survival rate. With a delay in administration to 36 h after inoculation, the efficacy of the cephalosporins decreased markedly. In the three dosages tested, cefazolin was ineffective. Survival improved with the administration of nine doses of 60 mg of cefotaxime per kg or nine doses of 10 mg of ceftazidime per kg. These results are not in accordance with the ratio of in vitro activities of cefotaxime and ceftazidime or the serum concentration curves. Images

Bakker-Woudenberg, I A; van den Berg, J C; Michel, M F

1982-01-01

216

Carbapenemase-producing Klebsiella pneumoniae in the Czech Republic in 2011.  

PubMed

Carbapenemase-producing Enterobacteriaceae and Pseudomonas spp. are increasingly reported in many countries all over the world. Due to the resistance of those bacteria to almost all antibiotics (e.g.beta-lactams, aminoglycosides, fluoroquinolones),treatment options are seriously limited. In the Czech Republic, the incidence of carbapenemase-producing Enterobacteriaceae seems to be low, restricted to only three cases detected between 2009 and 2010.Here, we describe molecular typing of 15 carbapenemase-producing Klebsiella pneumoniae isolates identified in the Czech Republic during 2011. Five VIM-1-producing isolates belonging to sequence type (ST)11 and one VIM-4-producing isolate of ST1029 have been detected. blaVIM-1 and blaVIM-4 as a part of class 1 integrons were chromosomally located or carried by a plasmid belonging to A/C replicon type (blaVIM-4). KPC-3-producing isolates of ST512, recovered from six patients, caused an outbreak. Three more isolates producing KPC-2 enzyme belonged to ST258. Both blaKPCgenes were part of the Tn4401a transposon carried on plasmids of the pKpQIL type. The isolates were resistant to all antibiotics tested except colistin and/or gentamicin.Four of these 15 strains were recovered from patients repatriated to the Czech Republic from Greece and Italy. This is the first report of outbreaks caused by carbapenemase-producing Enterobacteriaceae in the Czech Republic. PMID:24229789

Hrabák, J; Papagiannitsis, C C; Študentová, V; Jakubu, V; Fridrichová, M; Zemlickova, H

2013-01-01

217

NMR solution structure of KP-TerB, a tellurite-resistance protein from Klebsiella pneumoniae  

PubMed Central

Klebsiella pneumoniae (KP), a Gram-negative bacterium, is a common cause of hospital-acquired bacterial infections worldwide. Tellurium (Te) compounds, although relatively rare in the environment, have a long history as antimicrobial and therapeutic agents. In bacteria, tellurite (TeO3 ?2) resistance is conferred by the ter (Ter) operon (terZABCDEF). Here, on the basis of 2593 restraints derived from NMR analysis, we report the NMR structure of TerB protein (151 amino acids) of KP (KP-TerB), which is mainly composed of seven ?-helices and a 310 helix, with helices II to V apparently forming a four-helix bundle. The ensemble of 20 NMR structures was well-defined, with a RMSD of 0.32 ± 0.06 Å for backbone atoms and 1.11 ± 0.07 Å for heavy atoms, respectively. A unique property of the KP-TerB structure is that the positively and negatively charged clusters are formed by the N-terminal positively and C-terminal negatively charged residues, respectively. To the best of our knowledge, the protein sequence and structures of KP-TerB are unique.

Chiang, Sheng-Kuo; Lou, Yuan-Chao; Chen, Chinpan

2008-01-01

218

Multicellularity and Antibiotic Resistance in Klebsiella pneumoniae Grown Under Bloodstream-Mimicking Fluid Dynamic Conditions  

PubMed Central

Background.?While the importance of fluid dynamical conditions is well recognized in the growth of biofilms, their role during bacteremia is unknown. We examined the impact of physiological fluid shear forces on the development of multicellular aggregates of Klebsiella pneumoniae. Methods.?Wild-type and O-antigen or capsular mutants of K. pneumoniae were grown as broth culture in a Taylor-Couette flow cell configured to provide continuous shear forces comparable to those encountered in the human arterial circulation (ie, on the order of 1.0 Pa). The size distribution and antibiotic resistance of aggregates formed in this apparatus were determined, as was their ability to persist in the bloodstream of mice following intravenous injection. Results.?Unlike growth in shaking flasks, bacteria grown in the test apparatus readily formed aggregates, a phenotype largely absent in capsular mutants and to a lesser degree in O-antigen mutants. Aggregates were found to persist in the bloodstream of mice. Importantly, organisms grown under physiological shear were found to have an antibiotic resistance phenotype intermediate between that of fully planktonic and biofilm states. Conclusions.?When grown under intravascular-magnitude fluid dynamic conditions, K. pneumoniae spontaneously develops into multicellular aggregates that are capable of persisting in the circulation and exhibit increased antibiotic resistance.

Thornton, Margaret M.; Chung-Esaki, Hangyul M.; Irvin, Charlene B.; Bortz, David M.; Solomon, Michael J.; Younger, John G.

2012-01-01

219

Crystal structures of Klebsiella pneumoniae pantothenate kinase in complex with N-substituted pantothenamides.  

PubMed

N-Substituted pantothenamides are derivatives of pantothenate, the precursor in the biosynthesis of the essential metabolic cofactor coenzyme A (CoA). These compounds are substrates of pantothenate kinase (PanK) in the first step of CoA biosynthesis and possess antimicrobial activity against various pathogenic bacteria. Here we solved the crystal structure of the Klebsiella pneumoniae PanK (KpPanK) in complex with N-pentylpantothenamide (N5-Pan) to understand the molecular basis of its antimicrobial activity. The structure reveals a polar pocket interacting with the pantothenate moiety of N5-Pan and an aromatic pocket loosely protecting the pentyl tail, suggesting that the introduction of an aromatic ring to a new pantothenamide may enhance the compound's affinity to KpPanK. To test this idea, we synthesized N-pyridin-3-ylmethylpantothenamide (Np-Pan) and solved its co-crystal structure with KpPanK. The structure reveals two alternat conformations of the aromatic ring of Np-Pan bound at the aromatic pocket, providing the basis for further improvement of pantothenamide binding to KpPanK. PMID:23553820

Li, Buren; Tempel, Wolfram; Smil, David; Bolshan, Yuri; Schapira, Matthieu; Park, Hee-Won

2013-08-01

220

Experimental study on the growth of Salmonella and coli-aerogenes bacteria in pure and mixed cultures, in a fermentor, in two different enrichment media: Sodium selenite and tetrathionate broth  

Microsoft Academic Search

Different serotypes of Salmonella and coli-aerogenes bacteria were grown in a fermentor at +43°C. The Culture media used were composed of two different nutrient broths, one supplemented with sodium selenite, the other with potassium tetrathionate. The growth of both bacteria and the following types of mixed bacteria was studied: Escherichia coli-Salmonella brancaster and Klebsiella pneumoniae-Salmonella brancaster. During the first 10

B. Hugues; M. Plissier; A. Pagliardini; J. L. Plantat; J. Gaissa

1978-01-01

221

Sequential studies in ankylosing spondylitis. Association of Klebsiella pneumoniae with active disease  

Microsoft Academic Search

A study of 163 patients with ankylosing spondylitis seen on 433 occasions showed that active inflammatory disease was strongly associated with the presence of Klebsiella pneumoniae in the faeces (P less than 0.001). Sequential studies showed that in patients with inactive disease the presence of a positive culture for Klebsiella was associated with the subsequent development of active inflammatory disease

R W Ebringer; D R Cawdell; P Cowling; A Ebringer

1978-01-01

222

Klebsiella pneumoniae K1 Liver Abscess and Septic Endophthalmitis in a U.S. Resident  

PubMed Central

Klebsiella pneumoniae K1 is a major agent of hepatic abscess with metastatic disease in East Asia, with sporadic reports originating elsewhere. We report a case of abscess complicated by septic endophthalmitis caused by a wzyAKpK1-positive Klebsiella strain in a U.S. resident, raising concern for global emergence.

Sachdev, Darpun D.; Yin, Michael T.; Horowitz, Jason D.; Mukkamala, Sri Krishna; Lee, Song Eun

2013-01-01

223

Bacterial volatilization of mercury by immobilized bacteria in fixed and fluidized bed bioreactors  

Microsoft Academic Search

Pseudomonas aeruginosa and Klebsiella pneumoniae, mercury resistant bac- terial strains, which are able to grow at 1200 µM HgCl2 and to reduce mercuric ion to volatile metal mercury, were isolated from hydrocarbons-contaminated river in Morocco. These bacteria were used for removing mercury from synthetic water polluted by mercu- ry using fixed bioreactor and fluidized bed bioreactor. This mercury bio-decontamination system

F. Z. DZAIRI; Y. ZEROUAL; A. MOUTAOUAKKIL; J. TAOUFIK; M. TALBI; M. LOUTFI; K. LEE; M. BLAGHEN

224

Effects of electrolyzed oxidizing water and ice treatments on reducing histamine-producing bacteria on fish skin and food contact surface  

Microsoft Academic Search

This study investigated efficacy of electrolyzed oxidizing water (EO water) and ice (EO ice) treatments in reducing histamine-producing bacteria (Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Morganella morganii and Proteus hauseri) on food contact surfaces (ceramic tile and stainless steel) and fish skin (Atlantic salmon and yellowfin tuna). Soaking ceramic tile and stainless steel in EO water (50ppm chlorine) for 5min

Sureerat Phuvasate; Yi-Cheng Su

2010-01-01

225

Modulation of respiratory dendritic cells during Klebsiella pneumonia infection  

PubMed Central

Background Klebsiella pneumoniae is a leading cause of severe hospital-acquired respiratory tract infections and death but little is known regarding the modulation of respiratory dendritic cell (DC) subsets. Plasmacytoid DC (pDC) are specialized type 1 interferon producing cells and considered to be classical mediators of antiviral immunity. Method By using multiparameter flow cytometry analysis we have analysed the modulation of respiratory DC subsets after intratracheal Klebsiella pneumonia infection. Results Data indicate that pDCs and MoDC were markedly elevated in the post acute pneumonia phase when compared to mock-infected controls. Analysis of draining mediastinal lymph nodes revealed a rapid increase of activated CD103+ DC, CD11b+ DC and MoDC within 48 h post infection. Lung pDC identification during bacterial pneumonia was confirmed by extended phenotyping for 120G8, mPDCA-1 and Siglec-H expression and by demonstration of high Interferon-alpha producing capacity after cell sorting. Cytokine expression analysis of ex vivo-sorted respiratory DC subpopulations from infected animals revealed elevated Interferon-alpha in pDC, elevated IFN-gamma, IL-4 and IL-13 in CD103+ DC and IL-19 and IL-12p35 in CD11b+ DC subsets in comparison to CD11c+ MHC-class IIlow cells indicating distinct functional roles. Antigen-specific naive CD4+ T cell stimulatory capacity of purified respiratory DC subsets was analysed in a model system with purified ovalbumin T cell receptor transgenic naive CD4+ responder T cells and respiratory DC subsets, pulsed with ovalbumin and matured with Klebsiella pneumoniae lysate. CD103+ DC and CD11b+ DC subsets represented the most potent naive CD4+ T helper cell activators. Conclusion These results provide novel insight into the activation of respiratory DC subsets during Klebsiella pneumonia infection. The detection of increased respiratory pDC numbers in bacterial pneumonia may indicate possible novel pDC functions with respect to lung repair and regeneration.

2013-01-01

226

Structure and function of class 1 integron in clinical isolates of Klebsiella pneumoniae.  

PubMed

To investigate molecular mechanism of multi-resistance of Klebsiella pneumoniae and its spreading, 179 strains isolated from different clinical samples in the period of 2002-2007 with serious resistance to 14 anti-bacterial agents were examined. Among them, 118 (65.9%) were resistant to at least two anti-bacterial agents; 36.3% (65/179) were found to contain class 1 integrons. There was a significant difference for resistance rate between the integron positive and the negative groups, especially for antimicrobial agents of aminoglycosides, quinolones and sulfonamides (P<0.01). Gene cassette structures of the class 1 integrons in these bacteria were analyzed and their resistance genes were further cloned and tested for antibiotic resistance activities. Fifteen gene cassettes were identified with dfrA17-aadA5 being the most popular form. Three recombinant plasmids pET28a-dhfr17, pET28a-dhfr17-orfF and pET28a-dhfr17-orfF-aadA2 were cloned from a gene cassette of dhfr17-orfF-aadA2. When introduced into a recipient E. coli strain BL21, all of them rendered resistance to co-trimoxazole, with minimum inhibitory concentration (MIC) value up to 256 µg/µL. The E. coli BL21 carrying pET28a- dhfr17 or pET28a-dhfr17-orfF had the same MIC value of 8 µg/µL to streptomycin as the recipient strain without plasmid. However, the E. coli carrying pET28a-dhfr17-orfF-aadA2 was resistant to streptomycin with MIC level up to 256 µg/µL. In conclusion, class 1 integrons were regularly identified in Klebsiella pneumoniae. They mainly carry resistance genes against antimicrobial agents of aminoglycosides and sulfonamide. Transferable plasmid carrying integrons with resistance genes may play an important role in resistance spreading among bacterial species. PMID:24929519

Yuejin, Zhang; Qingli, Chang; Qian, Wang; Junwan, Lu; Huan, Wang; Peizhen, Li; Jun, Ying; Qiyu, Bao; Yunliang, Hu

2014-06-20

227

Plasmid mediated antibiotic resistance in marine bacteria.  

PubMed

This research work was conducted in Uppanar estuary to ascertain the role of plasmids in the antibiotic resistance of bacteria. Water and sediment samples were collected for a period of three months. When tested against 20 antibiotics 22 MAR strains were isolated from the samples, which were found resistant to 5-13 antibiotics. They belong to 7 genera and 10 species. Gram-negative bacteria namely Neisseria mucosa, N. sicca, Branhamella catarrhalis, Klebsiella ozaenae, Citrobacterintermedius, Pseudomonas fluorescens and Enterobacter aerogenes were isolated. Gram-positive bacteria were of Bacillus subtilis, B. megaterium and Micrococcus luteus. When plasmid curing was done using acredine orange, the resistance against penicillin-G, ampicillin, tetracycline, amoxycillin, kanamycin, and chloramphenicol were totally lost in all strains, which confirmed the role of plasmid in these strains against antibiotics. Ten strains belong to different species were selected for the plasmid isolation and electrophoresis was done. Presence of plasmids in all strains was confirmed and the molecular weight was in the range of 2850 to 3170 bp. The study revealed that MAR strains are common in Uppanar estuary and they are plasmid mediated. This environment is seemed to be deteriorating at an alarming rate. PMID:18380085

Thavasi, R; Aparnadevi, K; Jayalakshmi, S; Balasubramanian, T

2007-07-01

228

Purification and vaccine potential of Klebsiella capsular polysaccharides.  

PubMed Central

Capsular polysaccharide (CPS) from 18 Klebsiella strains of different capsular types was isolated and characterized. Purified CPSs were composed primarily of carbohydrate with trace quantities of protein, nucleic acids, and lipopolysaccharide. All CPSs were of a high molecular weight, possessing a Kd of 0.01 to 0.11 as determined by gel filtration over Sepharose CL-4B. Low levels of lipopolysaccharide present in all preparations were responsible for the highly pyrogenic nature of one-half of the CPS preparations. Treatment of capsular material with dilute NaOH in 95% ethanol markedly reduced the pyrogenicity of all preparations and had a negligible effect on their molecular weight. The immunogenicity of the various native CPSs for mice varied considerably from serotype to serotype, but all evoked an anticapsular immunoglobulin G response. Five of 18 NaOH-treated polysaccharides were significantly (P less than 0.05) less immunogenic than their native counterparts. Human immunoglobulin G prepared from volunteers immunized with either native or NaOH-treated KP1-0 capsular polysaccharide was equally effective at preventing experimental fatal Klebsiella pneumoniae burn wound sepsis in mice.

Cryz, S J; Furer, E; Germanier, R

1985-01-01

229

Genotypic and phenotypic characters and nosocomial significance of bacteria endemic in neonatal intensive care units.  

PubMed

The degree of colonization was determined by complex typing (sero-, phage, colicin-, pyocin typing, plasmid profile analysis) of 212 Escherichia coli, 232 Klebsiella, 117 Pseudomonas aeruginosa and 52 Staphylococcus aureus strains isolated from nose, throat, ear and other sources of 563 new-born infants in gynaecological and maternity wards of two neonatal intensive care units (NICU I and II) during a one year period. The presence of Klebsiella strains was more frequent in NICU I and E. coli and P. aeruginosa in NICU II, S. aureus occurred in a low level in both units. In NICU I 34 kinds, in NICU II 43 kinds of E. coli serotype were found. In NICU I the accumulation of serotypes O6:H-, O6:H1, O19:H-, in NICU II O4:H-, O6:H1 was observed. The Klebsiella strains belonged in NICU I into 21, in NICU II into 12 phage types. Klebsiella was more frequent in NICU I than in NICU II, though the strains belonged to the same phage type in NICU II in 50.7%, but in NICU I 4 frequent and 19 rare phage types occurred. Sero- and pyocin typing was effective for typing of P. aeruginosa. The most frequent sero- and pyocin types were in NICU I:O11a,11b; in NICU II: O2a,2d,2f; 12v. The rate of antibiotic resistance in E. coli, Klebsiella, P. aeruginosa and S. aureus was nearly the same in both units, multiple resistance was more frequent in NICU I (except P. aeruginosa, it was multiple resistant in 100% in both units). In NICU I 267, in NICU II 174 infants were treated with antibiotics. The administration of penicillin derivatives was nearly similar in the two care units and the resistance among E. coli and Klebsiella strains was nearly the same too. Though, cephalosporins were used more frequently in NICU II, resistance to cephalosporins among E. coli and Klebsiella was a bit higher in NICU I. Aminoglycosides were more often used in NICU I, resistance to aminoglycosides among E. coli and Klebsiella was higher in this unit. The rate of isolation of the examined bacteria was significantly lower in the group treated with antibiotics, than in the untreated group. PMID:7804718

Milch, H; Czirók, E; Herpay, M; Gadó, I; Barcs, I

1994-01-01

230

Antibacterial properties of fish mucus from Channa punctatus and Cirrhinus mrigala.  

PubMed

Extracts and preparations made from the animal origin were used extensively in folk and modern medicine for treating many human diseases. In the present study efforts have been made to find the antimicrobial effect of the mucus of two bottom dwelling fresh water fishes namely, Channa punctatus and Cirrhinus mrigala. Fish mucus were tested against ten pathogenic bacteria such as Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Lactobacillus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella paratyphi, Salmonella typhi, Staphylococcus aureus and Vibrio cholera. The activity was measured in terms of zone of inhibition in mm. The mucus collected from Cirrhinus mrigala shows a strong inhibiting activity than the mucus of Channa punctatus. PMID:18700685

Kuppulakshmi, C; Prakash, M; Gunasekaran, G; Manimegalai, G; Sarojini, S

2008-01-01

231

KPC-producer gram negative bacteria among burned infants in Motahari Hospital, Tehran: first report from Iran  

PubMed Central

Summary To the best of our knowledge, this is the first report of Klebsiella, Acinetobacter and Pseudomonas-producing Klebsiella pneumoniae Carbapenemase (KPC) among burn infants in Iran. The objective of this study was to determine the phenotypic detection of these KPC among isolated Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella spp. A cross-sectional study was performed (February to September 2011) at a tertiary burn hospital in Tehran, Iran. Sixty-four strains were isolated from 20 patients. Strain and genus of isolates were confirmed, antibiotic susceptibility testing was implemented, and KPC determined by Modified Hodge Test. Fifteen of 36 strains (six Pseudomonas aeruginosa, six Acinetobacter baumannii, and three Klebsiella pneumoniae) were resistant to imipenem. Ten strains of 36 Gram negative isolates were resistant to all tested antibiotics except for Colistin. Thirteen of 15 resistant imipenem strains were confirmed as KPC-producer bacteria that isolated from nine patients. Six of 36 isolated strains were extended-spectrum ?-lactamase (ESBL)-producing bacteria, of which four strains were both KPC and ESBL. A high percentage of multidrug resistant (MDR) strains in our centre with positive KPC have created a major challenge in terms of mortality and morbidity. The findings of this study highlight the importance of implementing an effective infection control strategy to prevent and decrease the prevalence of KPC-producing organisms.

Azimi, L.; Rastegar Lari, A.; Alaghehbandan, R.; Alinejad, F.; Mohammadpoor, M.; Rahbar, M.

2012-01-01

232

Phagocytic and chemiluminescent responses of mouse peritoneal macrophages to living and killed Salmonella typhimurium and other bacteria  

SciTech Connect

In the presence of luminol, resident as well as thioglycolate-induced and immunized macrophages emitted chemiluminescence more efficiently when the cells were exposed to living Salmonella typhimurium than when they were exposed to the same bacterium killed by ultraviolet light or heat. This phenomenon was observed whether or not the bacterium was opsonized. The different response to living and killed bacteria was also found with Escherichia coli, Pseudomonas aeruginosa, Proteus morganii, and Enterobacter aerogenes, but not with Shigella sonnei, Klebsiella pneumoniae, and Propionibacterium acnes. The results suggest that macrophages respond better to living, motile bacteria than to nonmotile or killed bacteria. The experimental results obtained with motility mutants of S. typhimurium, E. coli, and P. aeruginosa confirm that macrophages exposed to the motile bacteria emit chemiluminescence more efficiently and ingest the motile bacteria at a much faster rate than the nonmotile bacteria.

Tomita, T.; Blumenstock, E.; Kanegasaki, S.

1981-06-01

233

Risk Factors for the First Episode of Klebsiella pneumoniae Resistant to Carbapenems Infection in Critically Ill Patients: A Prospective Study  

PubMed Central

Objective. To identify risk factors for the first episode of Klebsiella Pneumonia resistant to carbapenems (KPRC) infection in critically ill patients. Design, Setting, and Methods. This prospective cohort study was conducted in a 12-bed general Intensive Care Unit (ICU) in a University Hospital on ICU patients who required mechanical ventilation (MV) for >48 hours during a 12-month period. Clinical and microbiologic data were studied. Characteristics of KPRC patients were compared with those of critically ill patients who presented nonmultidrug resistant (MDR) bacterial infections or no documented infection at all. Results. Twenty-five patients presented KPRC infection, 18 presented non-MDR bacterial infection, and 39 patients presented no infection. Compared to patients without documented infection or infected by non MDR bacteria, patients with KPRC infection had received more frequently or for longer duration antibiotics against Gram-negative bacteria (carbapenems, colistin P < 0.05). Duration of colistin administration prior to KPRC isolation was independently associated with increased frequency of KPRC infection (odds ratio, 1.156 per day; 95% confidence interval, 1.010 to 1.312; P = 0.025). KPRC patients stayed longer in the ICU and received mechanical ventilation and sedation for longer periods and presented increased mortality (P < 0.05). Conclusion. KPRC infection is an emerging problem which might be more common in patients with previous use of antibiotics and especially colistin.

Mantzarlis, Konstantinos; Makris, Demosthenes; Manoulakas, Efstratios; Karvouniaris, Marios; Zakynthinos, Epaminondas

2013-01-01

234

Ethanol production from glycerol-containing biodiesel waste by Klebsiella variicola shows maximum productivity under alkaline conditions.  

PubMed

Biodiesel fuel (BDF) waste contains large amounts of crude glycerol as a by-product, and has a high alkaline pH. With regard to microbial conversion of ethanol from BDF-derived glycerol, bacteria that can produce ethanol at alkaline pH have not been reported to date. Isolation of bacteria that shows maximum productivity under alkaline conditions is essential to effective production of ethanol from BDF-derived glycerol. In this study, we isolated the Klebsiella variicola TB-83 strain, which demonstrated maximum ethanol productivity at alkaline pH. Strain TB-83 showed effective usage of crude glycerol with maximum ethanol production at pH 8.0-9.0, and the culture pH was finally neutralized by formate, a by-product. In addition, the ethanol productivity of strain TB-83 under various culture conditions was investigated. Ethanol production was more efficient with the addition of yeast extract. Strain TB-83 produced 9.8g/L ethanol (0.86mol/mol glycerol) from cooking oil-derived BDF waste. Ethanol production from cooking oil-derived BDF waste was higher than that of new frying oil-derived BDF and pure-glycerol. This is the first report to demonstrate that the K. variicola strain TB-83 has the ability to produce ethanol from glycerol at alkaline pH. PMID:24681408

Suzuki, Toshihiro; Nishikawa, Chiaki; Seta, Kohei; Shigeno, Toshiya; Nakajima-Kambe, Toshiaki

2014-05-25

235

Characterization of RarA, a Novel AraC Family Multidrug Resistance Regulator in Klebsiella pneumoniae  

PubMed Central

Transcriptional regulators, such as SoxS, RamA, MarA, and Rob, which upregulate the AcrAB efflux pump, have been shown to be associated with multidrug resistance in clinically relevant Gram-negative bacteria. In addition to the multidrug resistance phenotype, these regulators have also been shown to play a role in the cellular metabolism and possibly the virulence potential of microbial cells. As such, the increased expression of these proteins is likely to cause pleiotropic phenotypes. Klebsiella pneumoniae is a major nosocomial pathogen which can express the SoxS, MarA, Rob, and RamA proteins, and the accompanying paper shows that the increased transcription of ramA is associated with tigecycline resistance (M. Veleba and T. Schneiders, Antimicrob. Agents Chemother. 56:4466–4467, 2012). Bioinformatic analyses of the available Klebsiella genome sequences show that an additional AraC-type regulator is encoded chromosomally. In this work, we characterize this novel AraC-type regulator, hereby called RarA (Regulator of antibiotic resistance A), which is encoded in K. pneumoniae, Enterobacter sp. 638, Serratia proteamaculans 568, and Enterobacter cloacae. We show that the overexpression of rarA results in a multidrug resistance phenotype which requires a functional AcrAB efflux pump but is independent of the other AraC regulators. Quantitative real-time PCR experiments show that rarA (MGH 78578 KPN_02968) and its neighboring efflux pump operon oqxAB (KPN_02969_02970) are consistently upregulated in clinical isolates collected from various geographical locations (Chile, Turkey, and Germany). Our results suggest that rarA overexpression upregulates the oqxAB efflux pump. Additionally, it appears that oqxR, encoding a GntR-type regulator adjacent to the oqxAB operon, is able to downregulate the expression of the oqxAB efflux pump, where OqxR complementation resulted in reductions to olaquindox MICs.

Veleba, Mark; Higgins, Paul G.; Gonzalez, Gerardo; Seifert, Harald

2012-01-01

236

Klebsiella necrotizing soft tissue infections in liver transplant recipients: a case series.  

PubMed

Necrotizing soft tissue infections (NSTI) are rare but carry high mortality rates. NSTI with Klebsiella species have been previously described as associated with Klebsiella liver abscesses and endophthalmitis. Here, we describe 6 cases of NSTI in liver transplant recipients associated with Klebsiella pneumoniae, 4 of which were K. pneumoniae carbapenemase (KPC)-producing K. pneumoniae (CRKP). Increased awareness of this emerging pathogen and its association with necrotizing skin and soft tissue infection is critical, as early recognition and debridement may improve survival. Antimicrobial treatment of CRKP infections remains an ongoing challenge and implementation of enhanced infection control measures is essential. PMID:23782431

Rana, M M; Sturdevant, M; Patel, G; Huprikar, S

2013-08-01

237

Numerical taxonomy and ecology of petroleum-degrading bacteria.  

PubMed Central

A total of 99 strains of petroleum-degrading bacteria isolated from Chesapeake Bay water and sediment were identified by using numerical taxonomy procedures. The isolates, together with 33 reference cultures, were examined for 48 biochemical, cultural, morphological, and physiological characters. The data were analyzed by computer, using both the simple matching and the Jaccard coefficients. Clustering was achieved by the unweighted average linkage method. From the sorted similarity matrix and dendrogram, 14 phenetic groups, comprising 85 of the petroleum-degrading bacteria, were defined at the 80 to 85% similarity level. These groups were identified as actinomycetes (mycelial forms, four clusters), coryneforms, Enterobacteriaceae, Klebsiella aerogenes, Micrococcus spp. (two clusters), Nocardia species (two clusters), Pseudomonas spp. (two clusters), and Sphaerotilus natans. It is concluded that the degradation of petroleum is accomplished by a diverse range of bacterial taxa, some of which were isolated only at given sampling stations and, more specifically, from sediment collected at a given station.

Austin, B; Calomiris, J J; Walker, J D; Colwell, R R

1977-01-01

238

Cockroaches as carriers of bacteria in multi-family dwellings.  

PubMed Central

The potential risk of bacterial dissemination due to the presence of cockroaches (Blattella germanica, Blattellidae) in low-income flats was investigated. Cockroaches can carry a great variety of bacterial species; we identified 30 different species from 52 different flats. Klebsiella oxycytoca, K. pneumoniae and Enterobacter cloacae were the most frequently found. Pathogenic and potentially pathogenic bacteria represented 54% of all the bacterial identifications. Bacteria were carried either on the cuticle or in the gut. Contamination through external contact is sufficient to insure bacterial diffusion. There was a very low level of overlap estimated by Pianka's index (a) between the bacterial flora of neighbouring blocks of flats, and (b) between bacterial flora of different flats in the same block.

Cloarec, A.; Rivault, C.; Fontaine, F.; Le Guyader, A.

1992-01-01

239

Biodegradation of tributyl phosphate using Klebsiella pneumoniae sp. S3.  

PubMed

Tributyl phosphate (TBP) has enormous applications in the field of extraction, fuel reprocessing, as defoamers and/or plasticizers. Excessive usage of this organophosphorus compound, poses an environmental threat. The present study deals with microbial degradation of TBP using Klebsiella pneumoniae S3 isolated from the soil. Diauxic growth curve pattern explains a preferential utilization of TBP. The strain S3 was able to biotransform TBP (1,000 mg L?¹) to dibutyl phosphate within 48 h and showed higher tolerance towards TBP up to 17.0 g L?¹. Toxicity of the parent as well as degraded product was assessed using comet assay. Generation of reactive oxygen species elaborates the oxidative stress imposed upon the bacterial strain by TBP. The antioxidant defense mechanism was studied using various biomarkers namely catalase, glutathione-S-transferase, and superoxide dismutase. The present study describes a faster and eco-friendly alternative for disposal of TBP. PMID:23644771

Kulkarni, S V; Markad, V L; Melo, J S; D'Souza, S F; Kodam, K M

2014-01-01

240

Acetylene reduction (dinitrogen fixation) by clinical isolates of Klebsiella pneumoniae.  

PubMed Central

Freshly isolated clinical strains of Klebsiella were tested for the ability to fix dinitrogen by the acetylene reduction assay. Ability to detect this trait was markedly affected by cultural conditions. When the test was run at 37 degrees C in the presence of yeast extract (50 mg/liter), only 1.6% of the organisms were diazotrophs, whereas this temperature without yeast extract yielded 12.9% positive cultures. The optimum condition found was 28 degrees C without yeast extract (21.9% positive); therefore, search for diazotrophy in clinical strains should not be conducted at the usual incubation temperature. There was a high incidence of indole-positive strains among diazotrophs. No such correlation was noted with any other biochemical trait or antibiotic susceptibility tested. The significance of this correlation is not apparent.

Chambers, C A; Silver, W S

1977-01-01

241

Klebsiella pneumoniae liver abscess in an immunocompetent child  

PubMed Central

Klebsiella pneumoniae has emerged as a leading pathogen that causes pyogenic liver abscesses (PLAs) in Korea. K. pneumoniae liver abscess (KLA) is potentially life threatening, and the diagnosis is difficult. In developed countries, PLA is rarely observed in children and is frequently associated with disorders of granulocyte function and previous abdominal infection. We observed a case of KLA in a healthy 12-year-old boy. To our knowledge, this is the first reported case of KLA in an immunocompetent child without an underlying disease in Korea. The patient was treated with percutaneous catheter drainage and antibiotics. The catheter was placed in the intrahepatic abscess for 3 weeks and parenteral antibiotics (ceftriaxone and amikacin) were administered for 4 weeks, followed by oral antibiotics (cefixime) for 2 weeks. We reported this case to raise awareness of KLA in immunocompetent children among physicians, and to review the diagnosis, risk factors, potential complications, and appropriate treatment of KLA.

Kwon, Jang-Mi; Shim, Jae Won; Kim, Deok Soo; Shim, Jung Yeon; Park, Moon Soo

2013-01-01

242

Metabolism of benzonitrile and butyronitrile by Klebsiella pneumoniae  

SciTech Connect

A strain of Klebsiella pneumoniae that used aliphatic nitriles as the sole source of nitrogen was adapted to benzonitrile as the sole source of carbon and nitrogen. Gas chromatographic and mass spectral analyses of culture filtrates indicated that K. pneumoniae metabolized 8.4 mM benzonitrile to 4.0 mM benzoic acid and 2.7 mM ammonia. In addition, butyronitrile was metabolized to butyramide and ammonia. The isolate also degraded mixtures of benzonitrile and aliphatic nitriles. Cell extracts contained nitrile hydratase and amidase activities. The enzyme activities were higher with butyronitrile and butyramide than with benzonitrile and benzamide, and amidase activities were twofold higher than nitrile hydratase activities. K. pneumoniae appears promising for the bioremediation of sites contaminated with aliphatic and aromatic nitriles.

Nawaz, M.S.; Heinze, T.M.; Cerniglia, C.E. (Food and Drug Administration, Jefferson, AK (United States))

1992-01-01

243

Cloning and expression of the Klebsiella pneumoniae galactose operon.  

PubMed

The entire galactose (gal) operon of Klebsiella pneumoniae was isolated and functionally analyzed in Escherichia coli. The genes encoding galactokinase (galK), galactose-1-phosphate uridyltransferase (galT), and UDP-galactose-4-epimerase (galE) were mapped by complementation analysis. The gene order E-T-K was found to be identical to that of Salmonella spp. and E. coli. Analysis of the nucleotide sequence in the control region revealed significant homology with that of E. coli. Two major sites for transcriptional initiation, both mapped to a cytosyl residue, were identified by primer extension. When the operon is expressed in E. coli, the K. pneumoniae gal gene products make up about 30% of the total cellular proteins. The presence of a powerful promoter responsible for high level synthesis of the gal proteins was also demonstrated using beta-galactosidase as reporter. PMID:1478918

Peng, H L; Fu, T F; Liu, S F; Chang, H Y

1992-11-01

244

Structure of the capsular polysaccharide of Klebsiella serotype K40.  

PubMed

The capsular polysaccharide from Klebsiella Serotype K40 contains D-galactose, D-mannose, L-rhamnose, and D-glucuronic acid in the ratios of 4:1:1:1. Methylation analysis of the native and carboxyl-reduced polysaccharide provided information about the glycosidic linkages in the repeating unit. Degradation of the permethylated polymer with base established the identity of the sugar unit preceding the glycosyluronic acid residue. The modes of linkages of different sugar residues were further confirmed by Smith degradation and partial hydrolysis of the K40 polysaccharide. The anomeric configurations of the different sugar residues were determined by oxidation of the peracetylated native and carboxyl-reduced polysaccharide with chromium trioxide. Based on all of these results, the heptasaccharide structure 1 was assigned to the repeating unit of the K40 polysaccharide. (Formula: see text) PMID:3664521

Ray, A K; Roy, A; Roy, N

1987-07-15

245

Structural investigation of Klebsiella serotype K46 polysaccharide.  

PubMed

The structure of the capsular polysaccharide from Klebsiella type K46 has been investigated by using the techniques of methylation analysis, periodate oxidation, and partial hydrolysis. The anomeric linkages were determined by 1H- and 13C-n.m.r. spectroscopy of the polysaccharide and of derived poly- and oligo-saccharides obtained through degradative procedures. 1H-N.m.r. spectroscopy of the polysaccharide in D2O showed clearly a ratio of one (1-carboxyethylidene) group (CH3, delta 1.47) to six anomeric protons (delta 4.62--5.29). The polysaccharide was shown to consist of the following hexasaccharide repeating unit, which is unique in this series in having a (1-carboxyethylidene) acetal group on a lateral, but nonterminal, sugar residue. (Formula: see text). PMID:7438134

Okutani, K; Dutton, G G

1980-11-15

246

A multiple antibiotic and serum resistant oligotrophic strain, Klebsiella pneumoniae MB45 having novel dfrA30, is sensitive to ZnO QDs  

PubMed Central

Background The aim of this study was to describe a novel trimethoprim resistance gene cassette, designated dfrA30, within a class 1 integron in a facultatively oligotrophic, multiple antibiotic and human serum resistant test strain, MB45, in a population of oligotrophic bacteria isolated from the river Mahananda; and to test the efficiency of surface bound acetate on zinc oxide quantum dots (ZnO QDs) as bactericidal agent on MB45. Methods Diluted Luria broth/Agar (10-3) media was used to cultivate the oligotrophic bacteria from water sample. Multiple antibiotic resistant bacteria were selected by employing replica plate method. A rapid assay was performed to determine the sensitivity/resistance of the test strain to human serum. Variable region of class 1 integron was cloned, sequenced and the expression of gene coding for antibiotic resistance was done in Escherichia coli JM 109. Identity of culture was determined by biochemical phenotyping and 16S rRNA gene sequence analyses. A phylogenetic tree was constructed based on representative trimethoprim resistance-mediating DfrA proteins retrieved from GenBank. Growth kinetic studies for the strain MB45 were performed in presence of varied concentrations of ZnO QDs. Results and conclusions The facultatively oligotrophic strain, MB45, resistant to human serum and ten antibiotics trimethoprim, cotrimoxazole, ampicillin, gentamycin, netilmicin, tobramycin, chloramphenicol, cefotaxime, kanamycin and streptomycin, has been identified as a new strain of Klebsiella pneumoniae. A novel dfr gene, designated as dfrA30, found integrated in class 1 integron was responsible for resistance to trimethoprim in Klebsiella pneumoniae strain MB45. The growth of wild strain MB45 was 100% arrested at 500 mg/L concentration of ZnO QDs. To our knowledge this is the first report on application of ZnO quantum dots to kill multiple antibiotics and serum resistant K. pneumoniae strain.

2011-01-01

247

Activation of IFN-?/STAT/IRF-1 in Hepatic Responses to Klebsiella pneumoniae Infection  

PubMed Central

Background Klebsiella pneumoniae-caused liver abscess (KLA) has become a health problem in Taiwan and is continually reported in other countries. Diabetes mellitus, the most common metabolic disorder, underlies half of the KLA patients in Taiwan. The clinical impact of KLA has been well-documented. Nevertheless, the molecular basis regarding how K. pneumoniae causes liver infection, particularly in diabetic individuals, remains unclear. Methodology/Principle Findings Auto-bioluminescence-expressing K. pneumoniae was inoculated into diabetic mice and age-match naïve control. With the use of in vivo imaging system, translocation of the bioluminescence-expressing K. pneumoniae from intestine to extraintestinal organs, mainly the liver, was noted in 80% of the diabetic mice, whereas the same bacteria causes extraintestinal infections in only 31% of naïve mice. Besides increased morbidity, the severity of hepatic tissue injury was also enhanced in the K. pneumoniae-infected diabetic mice. Upon K. pneumoniae infection, IFN-? production was significantly evoked in the liver. To mediate IFN-? signal, STAT (signal transducers and activators of transcription) 1 and 3 were activated in hepatocytes, and so was the expression of IRF (interferon regulatory factor)-1. Moreover, accumulation of neutrophils which was triggered by prolonged production of IL-1? and MIP-2, and significant increases in the level of active caspase 3 and phospho-eIF2?, were exclusively revealed in the K. pneumoniae-infected diabetic mice. Conclusion The activation of IFN-?/STAT/IRF-1 signaling demonstrated by this work emphasizes the role of IFN-? for mediating the hepatic response to K. pneumoniae infection.

Lin, Yi-Chun; Lu, Min-Chi; Lin, Chingju; Chiang, Ming-Ko; Jan, Ming-Shiou; Tang, Hui-Ling; Liu, Hsu-Chung; Lin, Wea-Lung; Huang, Chih-Yang; Chen, Chuan-Mu; Lai, Yi-Chyi

2013-01-01

248

Treatment of Klebsiella Pneumoniae Carbapenemase (KPC) infections: a review of published case series and case reports  

PubMed Central

The emergence of Klebsiella pneumoniae carbapenemases (KPCs) producing bacteria has become a significant global public health challenge while the optimal treatment remains undefined. We performed a systematic review of published studies and reports of treatment outcomes of KPC infections using MEDLINE (2001–2011). Articles or cases were excluded if one of the following was fulfilled: no individual patient data provided, no treatment regimen specified, no treatment outcome specified, report of colonization, or greater than three antibiotics were used to treat the KPC infection. Data extracted included patient demographics, site of infection, organism, KPC subtype, antimicrobial therapy directed at KPC-infection, and treatment outcome. Statistical analysis was performed in an exploratory manner. A total of 38 articles comprising 105 cases were included in the analysis. The majority of infections were due to K. pneumoniae (89%). The most common site of infection was blood (52%), followed by respiratory (30%), and urine (10%). Forty-nine (47%) cases received monotherapy and 56 (53%) cases received combination therapy directed at the KPC-infection. Significantly more treatment failures were seen in cases that received monotherapy compared to cases who received combination therapy (49% vs 25%; p= 0.01). Respiratory infections were associated with higher rates of treatment failure with monotherapy compared to combination therapy (67% vs 29% p= 0.03). Polymyxin monotherapy was associated with higher treatment failure rates compared to polymyxin-based combination therapy (73% vs 29%; p= 0.02); similarly, higher treatment failure rates were seen with carbapenem monotherapy compared to carbapenem-based combination therapy (60% vs 26%; p= 0.03). Overall treatment failure rates were not significantly different in the three most common antibiotic-class combinations: polymyxin plus carbapenem, polymyxin plus tigecycline, polymyxin plus aminoglycoside (30%, 29%, and 25% respectively; p=0.6). In conclusion, combination therapy is recommended for the treatment of KPC infections; however, which combination of antimicrobial agents needs to be established in future prospective clinical trials.

2012-01-01

249

Characterization of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae from Riyadh, Saudi Arabia.  

PubMed

The objectives of this study were to determine the prevalences, genotypes, and clonal relationships of extended-spectrum beta-lactamase (ESBL)-producing strains in 98 Klebsiella pneumoniae isolates from Riyadh. The prevalence of ESBLs in these strains was 37·75%. All isolates that were confirmed to have ESBLs were completely resistant to amoxicillin/clavulanate, aztreonam, cefotaxime, ceftazidime, cefoxitin, and gentamicin and were susceptible to tigecycline, colistin, and imipenem. In total, 16·6, 77, and 91·6% of isolates were resistant to amikacin, ciprofloxacin, and piperacillin/tazobactam, respectively. The prevalences of isolates producing the beta-lactamases SHV, CTX-M, and TEM were 91·9, 86·5, and 54·05%, respectively. The most frequent ESBL gene detected was blaCTX-M-15, which was observed in 75% of isolates. Other frequent ESBL genes were blaSHV-12 (29·73% of isolates) and blaSHV-5 (5·4% of isolates); additionally, blaCTX-M-3, blaCTX-M-27, blaCTX-M-57, and blaCTX-M-82 were each detected in one isolate. Pulsed-field gel electrophoresis (PFGE) analysis revealed the presence of diverse and unrelated clones. The high prevalence of ESBL producers among the strains examined in our study was not due to the spread of a single clone of bacteria. Clone A was detected in six isolates, indicating intra-hospital spread. Our study documented a high prevalence of the CTX-M-15 product in K. pneumoniae and demonstrated that SHV-12 was also highly prevalent. This study represents the first report of CTX-M-3, CTX-M-27, CTX-M-57, and CTX-M-82 beta-lactamases in K. pneumoniae isolates from Saudi Arabia. PMID:24091155

Al-Qahtani, Ahmed A; Al-Agamy, Mohamed H; Ali, Mohamed S; Al-Ahdal, Mohammad N; Aljohi, Mohammad A; Shibl, Atef M

2014-06-01

250

Molecular characterization of clinical multidrug-resistant Klebsiella pneumoniae isolates  

PubMed Central

Background Klebsiella pneumoniae is a frequent nosocomial pathogen, with the multidrug-resistant (MDR) K. pneumoniae being a major public health concern, frequently causing difficult-to-treat infections worldwide. The aim of this study was to investigate the molecular characterization of clinical MDR Klebsiella pneumoniae isolates. Methods A total of 27 non-duplicate MDR K. pneumoniae isolates with a CTX-CIP-AK resistance pattern were investigated for the prevalence of antimicrobial resistance genes including extended spectrum ?-lactamase genes (ESBLs), plasmid-mediated quinolone resistance (PMQR) genes, 16S rRNA methylase (16S-RMTase) genes, and integrons by polymerase chain reaction (PCR) amplification and DNA sequencing. Plasmid replicons were typed by PCR-based replicon typing (PBRT). Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were carried out to characterize the strain relatedness. Results All the isolates co-harbored 3 or more resistance determinants. OqxAB, CTX-M-type ESBLs and RmtB were the most frequent determinants, distributed among19 (70.4%),18 (66.7%) and 8 (29.6%) strains. Fourteen isolates harbored class 1 integrons, with orfD-aacA4 being the most frequent gene cassette array. Class 3 integrons were less frequently identified and contained the gene cassette array of blaGES-1-blaOXA-10-aac(6?)-Ib. IncFII replicon was most commonly found in this collection. One cluster was observed with ?80% similarity among profiles obtained by PFGE, and one sequence type (ST) by MLST, namely ST11, was observed in the cluster. Conclusion K. pneumoniae carbapenemase (KPC)–producing ST11 was the main clone detected. Of particular concern was the high prevalence of multiple resistance determinants, classs I integrons and IncFII plasmid replicon among these MDR strains, which provide advantages for the rapid development of MDR strains.

2014-01-01

251

Subhuman Primate Model for the Study of Infection Induced by 'Klebsiella pneumoniae'.  

National Technical Information Service (NTIS)

Squirrel monkeys were instilled intratracheally with 700 Klebsiella pneumoniae organisms and developed lobar pneumonia in about 24 h. Characteristic clinical findings were fever, anorexia, and coughing. Laboratory findings included leukocytosis or leukope...

R. F. Berendt G. L . Knutsen M. C. Powanda

1978-01-01

252

Identification of two chemical types of K21 capsular polysaccharide from klebsiellae.  

PubMed

Strains of Klebsiella pneumoniae of serotype K21 are frequently involved in outbreaks of nosocomial infections. The type strain of Klebsiella pneumoniae K21 (which we have renamed K21a) produces capsular polysaccharide that contains mannose, galactose and glucuronic acid in the ratio 2:2:1. In contrast, all eight of the randomly chosen isolates of Klebsiella pneumoniae that were initially typed as K21 were shown by paper chromatography and NMR spectroscopy to produce a different capsular polysaccharide. We have designated this new polysaccharide K21b. The K21b capsular material appears to have a closely similar immunodominant side chain to K21a. However, K21b polysaccharide has two molecules of rhamnose in the polysaccharide backbone replacing the two molecules of mannose found in the K21a capsule. Our results suggest that the K21b Klebsiella serotype may be more frequently distributed than the classical K21a type. PMID:3116172

Allen, P M; Williams, J M; Hart, C A; Saunders, J R

1987-05-01

253

Coliform Bacteria and Nitrogen Fixation in Pulp and Paper Mill Effluent Treatment Systems  

PubMed Central

The majority of pulp and paper mills now biotreat their combined effluents using activated sludge. On the assumption that their wood-based effluents have negligible fixed N, and that activated-sludge microorganisms will not fix significant N, these mills routinely spend large amounts adding ammonia or urea to their aeration tanks (bioreactors) to permit normal biomass growth. N2 fixation in seven Eastern Canadian pulp and paper mill effluent treatment systems was analyzed using acetylene reduction assays, quantitative nitrogenase (nifH) gene probing, and bacterial isolations. In situ N2 fixation was undetectable in all seven bioreactors but was present in six associated primary clarifiers. One primary clarifier was studied in greater detail. Approximately 50% of all culturable cells in the clarifier contained nifH, of which >90% were Klebsiella strains. All primary-clarifier coliform bacteria growing on MacConkey agar were identified as klebsiellas, and all those probed contained nifH. In contrast, analysis of 48 random coliform isolates from other mill water system locations showed that only 24 (50%) possessed the nifH gene, and only 13 (27%) showed inducible N2-fixing activity. Thus, all the pulp and paper mill primary clarifiers tested appeared to be sites of active N2 fixation (0.87 to 4.90 mg of N liter?1 day?1) and a microbial community strongly biased toward this activity. This may also explain why coliform bacteria, especially klebsiellas, are indigenous in pulp and paper mill water systems.

Gauthier, Francis; Neufeld, Josh D.; Driscoll, Brian T.; Archibald, Frederick S.

2000-01-01

254

Surfactant Protein D Enhances Phagocytosis and Killing of Unencapsulated Phase Variants of Klebsiella pneumoniae  

Microsoft Academic Search

Pulmonary surfactant protein D (SP-D) is a collagenous C-type lectin (collectin) that is secreted into the alveoli and distal airways of the lung. We have studied the interactions of SP-D and alveolar macrophages with Klebsiella pneumoniae, a common cause of nosocomial pneumonia. SP-D does not agglutinate encapsulated K. pneumoniae but selectively agglutinates spontaneous, unencapsulated phase variants, such as Klebsiella strain

ITZHAK OFEK; ADI MESIKA; MOSHE KALINA; YONA KEISARI; RANIER PODSCHUN; HANY SAHLY; DONALD CHANG; DAVID MCGREGOR; ERIKA CROUCH

2001-01-01

255

Diversity of plasmids responsible for multiple resistance in Klebsiella serotype K2.  

PubMed Central

Klebsiella of capsular type K2 were investigated to find out whether a single epidemic clone was the source of many outbreaks of infection in different hospitals, in different areas over a period of five years. The klebsiellas studied were found to be very similar; they were of the same biotype, had similar klebecin sensitivity patterns and carried multiple drug-resistance plasmids; however, characterization of these plasmids showed that they were heterogeneous. Thus there was not a single epidemic bacterial clone.

Richards, H.; Hughes, V.; Datta, N.

1981-01-01

256

Klebsiella serotype 25 capsular polysaccharide: primary structure and depolymerization by a bacteriophage-borne glycanase.  

PubMed

By partial acid hydrolysis, methylation and gas-liquid chromatography-mass spectrometry of the methylated monomers (as the alditol acetates), mass spectrometry of trimethylsilylated disaccharide alditols, as well as proton magnetic resonance, the primary structure of the Klebsiella serotype 25 capsular polysaccharide was elucidated. A glycanase activity, associated with the particles of newly isolated Klebsiella bacteriophage no. 25, was shown to catalyze the hydrolysis of the glycan. PMID:853030

Niemann, H; Kwiatkowski, B; Westphal, U; Stirm, S

1977-04-01

257

Klebsiella serotype 25 capsular polysaccharide: primary structure and depolymerization by a bacteriophage-borne glycanase.  

PubMed Central

By partial acid hydrolysis, methylation and gas-liquid chromatography-mass spectrometry of the methylated monomers (as the alditol acetates), mass spectrometry of trimethylsilylated disaccharide alditols, as well as proton magnetic resonance, the primary structure of the Klebsiella serotype 25 capsular polysaccharide was elucidated. A glycanase activity, associated with the particles of newly isolated Klebsiella bacteriophage no. 25, was shown to catalyze the hydrolysis of the glycan. Images

Niemann, H; Kwiatkowski, B; Westphal, U; Stirm, S

1977-01-01

258

Glycolytic Breakdown of Sulfoquinovose in Bacteria: a Missing Link in the Sulfur Cycle  

PubMed Central

Sulfoquinovose (6-deoxy-6-sulfo-d-glucopyranose), formed by the hydrolysis of the plant sulfolipid, is a major component of the biological sulfur cycle. However, pathways for its catabolism are poorly delineated. We examined the hypothesis that mineralization of sulfoquinovose to inorganic sulfate is initiated by reactions of the glycolytic and/or Entner-Doudoroff pathways in bacteria. Metabolites of [U-13C]sulfoquinovose were identified by 13C-nuclear magnetic resonance (NMR) in strains of Klebsiella and Agrobacterium previously isolated for their ability to utilize sulfoquinovose as a sole source of carbon and energy for growth, and cell extracts were analyzed for enzymes diagnostic for the respective pathways. Klebsiella sp. strain ABR11 grew rapidly on sulfoquinovose, with major accumulations of sulfopropandiol (2,3-dihydroxypropanesulfonate) but no detectable release of sulfate. Later, when sulfoquinovose was exhausted and growth was very slow, sulfopropandiol disappeared and inorganic sulfate and small amounts of sulfolactate (2-hydroxy-3-sulfopropionate) were formed. In Agrobacterium sp. strain ABR2, growth and sulfoquinovose disappearance were again coincident, though slower than that in Klebsiella sp. Release of sulfate was still late but was faster than that in Klebsiella sp., and no metabolites were detected by 13C-NMR. Extracts of both strains grown on sulfoquinovose contained phosphofructokinase activities that remained unchanged when fructose 6-phosphate was replaced in the assay mixture with either glucose 6-phosphate or sulfoquinovose. The results were consistent with the operation of the Embden-Meyerhoff-Parnas (glycolysis) pathway for catabolism of sulfoquinovose. Extracts of Klebsiella but not Agrobacterium also contained an NAD+-dependent sulfoquinovose dehydrogenase activity, indicating that the Entner-Doudoroff pathway might also contribute to catabolism of sulfoquinovose.

Roy, Alexander B.; Hewlins, Michael J. E.; Ellis, Andrew J.; Harwood, John L.; White, Graham F.

2003-01-01

259

Removal of bacteria from stallion semen by colloid centrifugation.  

PubMed

Bacteria (environmental contaminants and occasionally potential pathogens) are found in most stallion ejaculates and may negatively affect sperm quality during storage. Since the use of antibiotics can lead to the development of resistance, an alternative means of microbial control is desirable. The removal of bacteria from stallion semen using Single Layer Centrifugation through Androcoll-E was investigated. Known doses of cultured bacteria were added to freshly collected ejaculates (15mL aliquots) before processing by Single Layer Centrifugation. The resulting sperm pellets and controls (not processed by Single Layer Centrifugation) were cultured and the bacteria identified. In experiment 1, doses of E. coli from 2×10(2) to 2×10(7) colony forming units were added to aliquots of semen. In experiment 2, Taylorella equigenitalis or a mix of E. coli, Klebsiella pneumoniae and Streptococcus equi subsp. zooepidemicus (approximately 7×10(6), 5×10(6), and 6×10(6)cfu, respectively) were added to 15mL aliquots of semen. In experiment 1, more than 90% of the bacteria were removed where loading doses were >×10(4)cfu/mL. In experiment 2, varying proportions of different bacteria were removed, ranging from 68% for naturally occurring Corynebacterium spp. to >97% for added cultured E. coli. Thus, Single Layer Centrifugation can separate spermatozoa from many, but not all bacteria in stallion ejaculates and could be a useful alternative to adding antibiotics to semen extenders to control bacterial contamination. However, further research is needed to determine the effect of small numbers of bacteria on sperm quality. PMID:24485764

Morrell, J M; Klein, C; Lundeheim, N; Erol, E; Troedsson, M H T

2014-02-01

260

Role of Antibiotic Penetration Limitation in Klebsiella pneumoniae Biofilm Resistance to Ampicillin and Ciprofloxacin  

PubMed Central

The penetration of two antibiotics, ampicillin and ciprofloxacin, through biofilms developed in an in vitro model system was investigated. The susceptibilities of biofilms and corresponding freely suspended bacteria to killing by the antibiotics were also measured. Biofilms of Klebsiella pneumoniae were developed on microporous membranes resting on agar nutrient medium. The susceptibilities of planktonic cultures and biofilms to 10 times the MIC were determined. Antibiotic penetration through biofilms was measured by assaying the concentration of antibiotic that diffused through the biofilm to an overlying filter disk. Parallel experiments were performed with a mutant K. pneumoniae strain in which ?-lactamase activity was eliminated. For wild-type K. pneumoniae grown in suspension culture, ampicillin and ciprofloxacin MICs were 500 and 0.18 ?g/ml, respectively. The log reductions in the number of CFU of planktonic wild-type bacteria after 4 h of treatment at 10 times the MIC were 4.43 ± 0.33 and 4.14 ± 0.33 for ampicillin and ciprofloxacin, respectively. Biofilms of the same strain were much less susceptible, yielding log reductions in the number of CFU of ?0.06 ± 0.06 and 1.02 ± 0.04 for ampicillin and ciprofloxacin, respectively, for the same treatment. The number of CFU in the biofilms after 24 h of antibiotic exposure was not statistically different from the number after 4 h of treatment. Ampicillin did not penetrate wild-type K. pneumoniae biofilms, whereas ciprofloxacin and a nonreactive tracer (chloride ion) penetrated the biofilms quickly. The concentration of ciprofloxacin reached the MIC throughout the biofilm within 20 min. Ampicillin penetrated biofilms formed by a ?-lactamase-deficient mutant. However, the biofilms formed by this mutant were resistant to ampicillin treatment, exhibiting a 0.18 ± 0.07 log reduction in the number of CFU after 4 h of exposure and a 1.64 ± 0.33 log reduction in the number of CFU after 24 h of exposure. Poor penetration contributed to wild-type biofilm resistance to ampicillin but not to ciprofloxacin. The increased resistance of the wild-type strain to ciprofloxacin and the mutant strain to ampicillin and ciprofloxacin could not be accounted for by antibiotic inactivation or slow diffusion since these antibiotics fully penetrated the biofilms. These results suggest that some other resistance mechanism is involved for both agents.

Anderl, Jeff N.; Franklin, Michael J.; Stewart, Philip S.

2000-01-01

261

Comparative analysis of diguanylate cyclase and phosphodiesterase genes in Klebsiella pneumoniae  

PubMed Central

Background Klebsiella pneumoniae can be found in environmental habitats as well as in hospital settings where it is commonly associated with nosocomial infections. One of the factors that contribute to virulence is its capacity to form biofilms on diverse biotic and abiotic surfaces. The second messenger Bis-(3’-5’)-cyclic dimeric GMP (c-di-GMP) is a ubiquitous signal in bacteria that controls biofilm formation as well as several other cellular processes. The cellular levels of this messenger are controlled by c-di-GMP synthesis and degradation catalyzed by diguanylate cyclase (DGC) and phophodiesterase (PDE) enzymes, respectively. Many bacteria contain multiple copies of these proteins with diverse organizational structure that highlight the complex regulatory mechanisms of this signaling network. This work was undertaken to identify DGCs and PDEs and analyze the domain structure of these proteins in K. pneumoniae. Results A search for conserved GGDEF and EAL domains in three sequenced K. pneumoniae genomes showed that there were multiple copies of GGDEF and EAL containing proteins. Both single domain and hybrid GGDEF proteins were identified: 21 in K. pneumoniae Kp342, 18 in K. pneumoniae MGH 78578 and 17 in K. pneumoniae NTUH-K2044. The majority had only the GGDEF domain, most with the GGEEF motif, and hybrid proteins containing both GGDEF and EAL domains were also found. The I site for allosteric control was identified only in single GGDEF domain proteins and not in hybrid proteins. EAL-only proteins, containing either intact or degenerate domains, were also identified: 15 in Kp342, 15 in MGH 78578 and 10 in NTUH-K2044. Several input sensory domains and transmembrane segments were identified, which together indicate complex regulatory circuits that in many cases can be membrane associated. Conclusions The comparative analysis of proteins containing GGDEF/EAL domains in K. pneumoniae showed that most copies were shared among the three strains and that some were unique to a particular strain. The multiplicity of these proteins and the diversity of structural characteristics suggest that the c-di-GMP network in this enteric bacterium is highly complex and reflects the importance of having diverse mechanisms to control cellular processes in environments as diverse as soils or plants and clinical settings.

2012-01-01

262

Rapid genotyping of Achromobacter xylosoxidans, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia isolates using melting curve analysis of RAPD-generated DNA fragments (McRAPD).  

PubMed

Typing of bacteria is important for monitoring newly emerging pathogens and for examining local outbreaks. We evaluated the randomly amplified polymorphic DNA technique in combination with melting curve analysis (McRAPD) of the amplified DNA fragments to genotype isolates from five Gram-negative species, i.e. Achromobacter xylosoxidans, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. By determining the melting temperature peaks of the amplified DNA fragments, we were able to distinguish the different genotypes of isolates, as they had been assessed by other genotyping techniques, i.e. agarose gel electrophoresis of RAPD fragments, multilocus sequence typing and/or AFLP™. According to our results, McRAPD may offer the possibility of genotyping a limited number of bacterial isolates, e.g. in case of suspicion of hospital outbreak, via a less costly, more rapid, less laborious and more user-friendly technique than RAPD followed by electrophoresis. PMID:21320595

Deschaght, Pieter; Van Simaey, Leen; Decat, Ellen; Van Mechelen, Els; Brisse, Sylvain; Vaneechoutte, Mario

2011-05-01

263

Klebsiella pneumoniae bacteraemia at an urban general hospital.  

PubMed

Of 47 patients with Klebsiella pneumoniae bacteraemia admitted to the Hillbrow Hospital, Johannesburg during a period of 18 months, 31 were males and 16 were females. Features predisposing to illness were found in 89.4% patients, chronic alcoholism, neoplastic disease and diabetes mellitus being the most common. Twenty-five infections were acquired in hospital and 22 in the community. Most patients (59.6%) had pneumonia. All isolates of K. pneumoniae were resistant to ampicillin (100%); several (42.6%) were resistant to other antibiotics also. The overall mortality rate was 55.3%. A higher mean initial blood pressure and lower concentrations of serum urea and bilirubin were found in survivors. None of the 28 patients, surviving more than 48 h who received combined therapy with an aminoglycoside and a beta-lactam antibiotic (to which the organism was susceptible) died. Among the remaining patients treated with either an appropriate beta-lactam agent alone, an appropriate aminoglycoside alone or ciprofloxacin the combined mortality rate was 83.3% (P = 0.007). PMID:2405058

Feldman, C; Smith, C; Levy, H; Ginsburg, P; Miller, S D; Koornhof, H J

1990-01-01

264

Properties of Klebsiella phage P13 and associated exopolysaccharide depolymerase  

NASA Astrophysics Data System (ADS)

The bacteriophage P13 that infects Klebsiella serotype K13 contains a heat-stable depolymerase capable of effective degradation of exopolysaccharide (EPS) produced by this microorganism. In this study, the titer of phage P13, initially 2.0 × 107 pfu mL-1, was found increasing 20 min after infection and reached 5.0 × 109 pfu mL-1 in 60 min. Accordingly, the enzyme activity of depolymerase approached the maximum 60 min after infection. Treatment at 70°C for 30 min inactivated all the phage, but retained over 90% of the depolymerase activity. Addition of acetone into the crude phage lysate led to precipitation of the protein, with a marked increase in bacterial EPS degradation activity and a rapid drop in the titer of phage. After partial purification by acetone precipitation and ultrafiltration centrifugation, the enzyme was separated from the phage particles, showing two components with enzyme activity on Q-Sepharose Fast Flow. The soluble enzyme had an optimum degradation activity at 60°C and pH 6.5. Transmission electron microscopy demonstrated that the phage P13 particles were spherical with a diameter of 50 nm and a short stumpy tail. It was a doublestrand DNA virus consisting of a nucleic acid molecule of 45976 bp. This work provides an efficient purification operation including thermal treatment and ultrafiltration centrifugation, to dissociate depolymerase from phage particles. The characterization of phage P13 and associated EPS depolymerase is beneficial for further application of this enzyme.

Liu, Yang; Li, Guiyang; Mo, Zhaolan; Chai, Zihan; Shang, Anqi; Mou, Haijin

2013-11-01

265

A Lemierre syndrome variant caused by Klebsiella pneumoniae.  

PubMed

Lemierre syndrome is an extremely rare disease characterized by oropharyngeal infection, septicemia, internal jugular vein thrombosis, and skip lesions. The most common causative pathogen is Fusobacterium necrophorum. We reported a 45-year-old woman who presented with left neck painful swelling and septicemia. Magnetic resonance imaging of the head and neck demonstrated venous thrombosis extending from the left internal jugular vein to the sigmoid sinus. During admission we discovered that the patient had uncontrolled diabetes mellitus. We also found a metastatic lesion through chest radiography. Klebsiella pneumoniae was cultivated from both blood samples and pus from deep neck spaces. Surgical drainage, early and adequate antibiotic treatment, anticoagulation, and strict control of blood glucose led to the patient's complete recovery. Because Lemierre syndrome is a forgotten disease in the era of antibiotics, awareness of the signs and symptoms of this disease is important because of its associated high mortality rate. This case illustrated that the presence of K pneumoniae can lead to Lemierre syndrome. PMID:22817819

Tsai, Yih-Jeng; Lin, Yu-Chi; Harnnd, Dor-Ji; Chiang, Rayleigh Ping-Ying; Wu, Hsing-Mei

2012-07-01

266

Enhanced 2,3-butanediol production by Klebsiella pneumoniae SDM.  

PubMed

Enhanced 2,3-butanediol (BD) production was carried out by Klebsiella pneumoniae SDM. The nutritional requirements for BD production by K. pneumoniae SDM were optimized statistically in shake flask fermentations. Corn steep liquor powder and (NH(4))(2)HPO(4) were identified as the most significant factors by the two-level Plackett-Burman design. Steepest ascent experiments were applied to approach the optimal region of the two factors and a central composite design was employed to determine their optimal levels. The optimal medium was used to perform fed-batch fermentations with K. pneumoniae SDM. BD production was then studied in a 5-l bioreactor applying different fed-batch strategies, including pulse fed batch, constant feed rate fed batch, constant residual glucose concentration fed batch, and exponential fed batch. The maximum BD concentration of 150 g/l at 38 h with a diol productivity of 4.21 g/l h was obtained by the constant residual glucose concentration feeding strategy. To the best of our knowledge, these results were new records on BD fermentation. PMID:18949476

Ma, Cuiqing; Wang, Ailong; Qin, Jiayang; Li, Lixiang; Ai, Xulu; Jiang, Tianyi; Tang, Hongzhi; Xu, Ping

2009-02-01

267

Fungi outcompete bacteria under increased uranium concentration in culture media.  

PubMed

As a key part of water management at the Ranger Uranium Mine (Northern Territory, Australia), stockpile (ore and waste) runoff water was applied to natural woodland on the mine lease in accordance with regulatory requirements. Consequently, the soil in these Land Application Areas (LAAs) presents a range of uranium concentrations. Soil samples were collected from LAAs with different concentrations of uranium and extracts were plated onto LB media containing no (0 ppm), low (3 ppm), medium (250 ppm), high (600 ppm) and very high (1500 ppm) uranium concentrations. These concentrations were similar to the range of measured uranium concentrations in the LAAs soils. Bacteria grew on all plates except for the very high uranium concentrations, where only fungi were recovered. Identifications based on bacterial 16S rRNA sequence analysis showed that the dominant cultivable bacteria belonged to the genus Bacillus. Members of the genera Paenibacillus, Lysinibacillus, Klebsiella, Microbacterium and Chryseobacterium were also isolated from the LAAs soil samples. Fungi were identified by sequence analysis of the intergenic spacer region, and members of the genera Aspergillus, Cryptococcus, Penicillium and Curvularia were dominant on plates with very high uranium concentrations. Members of the Paecilomyces and Alternaria were also present but in lower numbers. These findings indicate that fungi can tolerate very high concentrations of uranium and are more resistant than bacteria. Bacteria and fungi isolated at the Ranger LAAs from soils with high concentrations of uranium may have uranium binding capability and hence the potential for uranium bioremediation. PMID:23416228

Mumtaz, Saqib; Streten-Joyce, Claire; Parry, David L; McGuinness, Keith A; Lu, Ping; Gibb, Karen S

2013-06-01

268

Predominant association of Raoultella bacteremia with diseases of the biliary tract.  

PubMed

A case series of 14 patients with Raoultella bacteremia was compared with 28 Klebsiella oxytoca and 28 Klebsiella pneumoniae bacteremia cases. Forty-three percent of Raoultella bacteremia cases were associated with biliary tract disease, compared to 32% and 22% of patients with K. oxytoca and K. pneumoniae bacteremia, respectively. PMID:24325334

de Jong, Eefje; Erkens-Hulshof, Sandra; van der Velden, Lieven B J; Voss, Andreas; Bosboom, Ron; Hodiamont, Caspar J; Wever, Peter C; Rentenaar, Rob J; Sturm, Patrick D

2014-02-01

269

Bacteria Inactivation During Lithotripsy  

NASA Astrophysics Data System (ADS)

The influence of extracorporeal and intracorporeal lithotripsy on the viability of bacteria contained inside artificial kidney stones was investigated in vitro. Two different bacteria were exposed to the action of one extracorporeal shock wave generator and four intracorporeal lithotripters.

Del Sol Quintero, María; Mora, Ulises; Gutiérrez, Jorge; Mues, Enrique; Castaño, Eduardo; Fernández, Francisco; Loske, Achim M.

2006-09-01

270

Probiotic Bacteria and Methods.  

National Technical Information Service (NTIS)

Provided herein are molecular methods for assessing the state of gastrointestinal microflora of an animal, especially a species of poultry, and methods for identifying probiotic bacteria by comparing certain bacteria present in animals fed a diet not cont...

B. G. Harmon, C. L. Hofacre, M. D. Lee

2005-01-01

271

Effects of the hindlimb-unloading model of spaceflight conditions on resistance of mice to infection with Klebsiella pneumoniae  

NASA Technical Reports Server (NTRS)

BACKGROUND: It has been well documented in several studies that many immunologic parameters are altered in experimental animals and human subjects who have flown in space. However, it is not fully known whether these immunologic changes could result in increased susceptibility to infection. Hindlimb (antiorthostatic) unloading of rodents has been used successfully to simulate some of the effects of spaceflight on physiologic systems. OBJECTIVE: The objective of this study was to determine the effect of hindlimb unloading on the outcome of Klebsiella pneumoniae infection in mice. METHODS: Hindlimb-unloaded, hindlimb-restrained, and control mice were intraperitoneally infected with one 50% lethal dose of K pneumoniae 2 days after suspension. Mortality and bacterial load in several organs were compared among the groups. RESULTS: Unloaded mice showed significantly increased mortality and reduced mean time to death compared with that seen in the control groups. Kinetics of bacterial growth with smaller infective doses revealed that control mice were able to clear bacteria from the organs after 30 hours. In contrast, unloaded mice had continued bacterial growth at the same time point. CONCLUSION: The results of this study suggest that hindlimb unloading might enhance the dissemination of K pneumoniae, leading to increased mortality. The complex physiologic changes observed during hindlimb unloading, including stress, have a key role in the pathophysiology of this infection.

Belay, Tesfaye; Aviles, Hernan; Vance, Monique; Fountain, Kimberly; Sonnenfeld, Gerald

2002-01-01

272

Enhanced 2,3-butanediol production in recombinant Klebsiella pneumoniae via overexpression of synthesis-related genes.  

PubMed

2,3-Butanediol (2,3-BD) is a major metabolite produced by Klebsiella pneumoniae KCTC2242, which is a important chemical with wide applications. Three genes important for 2,3-BD biosynthesis acetolactate decarboxylase (budA), acetolactate synthase (budB), and alcohol dehydrogenase (budC) were identified in K. pneumoniae genomic DNA. With the goal of enhancing 2,3-BD production, these genes were cloned into pUC18K expression vectors containing the lacZ promoter and the kanamycin resistance gene to generate plasmids pSB1-7. The plasmids were then introduced into K. pneumoniae using electroporation. All strains were incubated in flask experiments and 2,3-BD production was increased by 60% in recombinant bacteria harboring pSB04 (budA and budB genes), compared with the parental strain K. pneumoniae KCTC2242. The maximum 2,3-BD production level achieved through fedbatch fermentation with K. pneumoniae SGJSB04 was 101.53 g/l over 40 h with a productivity of 2.54 g/l.h. These results suggest that overexpression of 2,3-BD synthesisrelated genes can enhance 2,3-BD production in K. pneumoniae by fermentation. PMID:22814501

Kim, Borim; Lee, Soojin; Park, Joohong; Lu, Mingshou; Oh, Minkyu; Kim, Youngrok; Lee, Jinwon

2012-09-01

273

Histopathologic evaluation of lung and extrapulmonary tissues show sex differences in Klebsiella pneumoniae - infected mice under different exposure conditions  

PubMed Central

It has been shown that female mice with pneumonia have a survival advantage over males, but this is reversed if ozone exposure precedes infection. The purpose of this study was to investigate factors that underlie these observations, by studying histopathologic changes in lung and extrapulmonary (spleen and liver) tissues after ozone or filtered air (FA) exposure followed by pulmonary bacterial infection. Male and female wild type C57BL/6J mice were exposed to ozone or FA, then anesthetized and infected intratracheally with Klebsiella pneumoniae bacteria. Tissues (lung, spleen, and liver) were subjected to histopathologic analysis at 48 h post-infection. We found that after infection, 1) the severity of inflammation was higher, the affected area of the lung was larger, and spleen red pulp myelopoiesis was lower in ozone-exposed mice compared to FA-exposed animals in both sexes; 2) more pronounced extrapulmonary lesions (in liver and spleen) were observed in FA-exposed males compared to FA-exposed females; and 3) excessive lung inflammatory response was detected in ozone-exposed females compared to ozone-exposed males. We concluded that different risk factors contribute to the differential outcome of pneumonia between sexes in the presence or absence of ozone-induced oxidative stress. In specific, the excessive lung inflammation and higher risk for extrapulmonary lesions in ozone-exposed infected females and in FA-exposed infected males appear to play, respectively, a dominant role in the previously observed respective survival outcomes.

Mikerov, Anatoly N; Cooper, Timothy K; Wang, Guirong; Hu, Sanmei; Umstead, Todd M; Phelps, David S; Floros, Joanna

2011-01-01

274

Specific modification of a Na+ binding site in NADH:quinone oxidoreductase from Klebsiella pneumoniae with dicyclohexylcarbodiimide.  

PubMed

The respiratory NADH:quinone oxidoreductase (complex I) (NDH-1) is a multisubunit enzyme that translocates protons (or in some cases Na+) across energy-conserving membranes from bacteria or mitochondria. We studied the reaction of the Na+-translocating complex I from the enterobacterium Klebsiella pneumoniae with N,N'-dicyclohexylcarbodiimide (DCCD), with the aim of identifying a subunit critical for Na+ binding. At low Na+ concentrations (0.6 mM), DCCD inhibited both quinone reduction and Na+ transport by NDH-1 concurrent with the covalent modification of a 30-kDa polypeptide. In the presence of 50 mM Na+, NDH-1 was protected from inhibition by DCCD, and the modification of the 30-kDa polypeptide with [14C]DCCD was prevented, indicating that Na+ and DCCD competed for the binding to a critical carboxyl group in NDH-1. The 30-kDa polypeptide was assigned to NuoH, the homologue of the ND1 subunit from mitochondrial complex I. It is proposed that Na+ binds to the NuoH subunit during NADH-driven Na+ transport by NDH-1. PMID:16621819

Vgenopoulou, Irini; Gemperli, Anja C; Steuber, Julia

2006-05-01

275

Destruction of single-species biofilms of Escherichia coli or Klebsiella pneumoniae subsp. pneumoniae by dextranase, lactoferrin, and lysozyme.  

PubMed

The aim of this work was to determine the destructive activity of dextranase, lactoferrin, and lysozyme, against single species biofilms composed of either Klebsiella pneumoniae subsp. pneumoniae or Escherichia coli using the MBEC Assay. Luminescence measurements based on quantitation of the ATP present were used to determine the amount of biofilm elimination and correlated with quantity of live bacteria present in the sample. The data were analyzed employing a two-way ANOVA and Bonferroni post-test. Treatments resulted in percentage reductions of E. coli biofilms ranging from 73 to 98%. Lactoferrin (40 microg/ml) produced a significantly higher-percentage reduction than lysozyme (10 microg/ml) (P < 0.05), no other significant differences occurred. Similar treatments resulted in percentage reductions of K. pneumoniae subsp. pneumoniae biofilms ranging from 51 to 100%. Dextranase treatments produced a significantly lower percentage reduction than all other materials (P < 0.05), no other significant differences occurred. No material was capable of complete destruction of both single species biofilms; however, low concentrations of lactoferrin and lysozyme each removed 100% of the K. pneumoniae subsp. pneumoniae biofilm. Low concentrations of lactoferrin or lysozyme might be beneficial to prevent biofilm formation by K. pneumoniae subsp. pneumoniae. PMID:23844477

Sheffield, Cynthia L; Crippen, Tawni L; Poole, Toni L; Beier, Ross C

2012-12-01

276

PCR-Based Identification of Klebsiella pneumoniae subsp. rhinoscleromatis, the Agent of Rhinoscleroma  

PubMed Central

Rhinoscleroma is a chronic granulomatous infection of the upper airways caused by the bacterium Klebsiella pneumoniae subsp. rhinoscleromatis. The disease is endemic in tropical and subtropical areas, but its diagnosis remains difficult. As a consequence, and despite available antibiotherapy, some patients evolve advanced stages that can lead to disfiguration, severe respiratory impairment and death by anoxia. Because identification of the etiologic agent is crucial for the definitive diagnosis of the disease, the aim of this study was to develop two simple PCR assays. We took advantage of the fact that all Klebsiella pneumoniae subsp. rhinoscleromatis isolates are (i) of capsular serotype K3; and (ii) belong to a single clone with diagnostic single nucleotide polymorphisms (SNP). The complete sequence of the genomic region comprising the capsular polysaccharide synthesis (cps) gene cluster was determined. Putative functions of the 21 genes identified were consistent with the structure of the K3 antigen. The K3-specific sequence of gene Kr11509 (wzy) was exploited to set up a PCR test, which was positive for 40 K3 strains but negative when assayed on the 76 other Klebsiella capsular types. Further, to discriminate Klebsiella pneumoniae subsp. rhinoscleromatis from other K3 Klebsiella strains, a specific PCR assay was developed based on diagnostic SNPs in the phosphate porin gene phoE. This work provides rapid and simple molecular tools to confirm the diagnostic of rhinoscleroma, which should improve patient care as well as knowledge on the prevalence and epidemiology of rhinoscleroma.

Fevre, Cindy; Passet, Virginie; Deletoile, Alexis; Barbe, Valerie; Frangeul, Lionel; Almeida, Ana S.; Sansonetti, Philippe; Tournebize, Regis; Brisse, Sylvain

2011-01-01

277

Antibiotic Resistance and Its Transfer Among Clinical and Nonclinical Klebsiella Strains in Botanical Environments †  

PubMed Central

A total of 183 isolates of Klebsiella from drinking water, market vegetables, wood, sawdust, industrial effluents, and human and animal origin were examined for susceptibility to 10 antibacterial agents. Incidence of resistance to two or more antibiotics tested was: 65% of the human clinical isolates, 59% among bovine mastitis, and 24% among the nonclinical isolates. The five different multiple resistance patterns among nonclinically derived Klebsiella were also found among the human and bovine mastitis isolates. Statistical analyses revealed that patterns of resistance among Klebsiella isolates from drinking water, market vegetables, and industrial effluents were highly correlated with each other and with resistance patterns of human clinical isolates. Antibiotic resistance was transferred between Klebsiella growing in two habitat-simulated environments (growing radish plants and aqueous sawdust suspensions). Transconjugants were detected in 5 of 21 and 6 of 21 mating pairs, respectively. Average transconjugants/donor ranged from 10?3 to 10?6 in Penassay broth, from 10?6 to 10?7 on radish plants, and from 10?5 to 10?8 in sawdust suspensions. Although antibiotic resistance transfer under simulated environmental conditions can occur, regrowth of clinical strains is probably the major cause for the widespread occurrence of antibiotic-resistant Klebsiella in the nonclinical environment.

Talbot, Henry W.; Yamamoto, Deborah K.; Smith, Martin W.; Seidler, Ramon J.

1980-01-01

278

NMR structure and calcium-binding properties of the tellurite resistance protein TerD from Klebsiella pneumoniae.  

PubMed

The tellurium oxyanion TeO(3)(2-) has been used in the treatment of infectious diseases caused by mycobacteria. However, many pathogenic bacteria show tellurite resistance. Several tellurite resistance genes have been identified, and these genes mediate responses to diverse extracellular stimuli, but the mechanisms underlying their functions are unknown. To shed light on the function of KP-TerD, a 20.5 -kDa tellurite resistance protein from a plasmid of Klebsiella pneumoniae, we have determined its three-dimensional structure in solution using NMR spectroscopy. KP-TerD contains a ?-sandwich formed by two five-stranded ?-sheets and six short helices. The structure exhibits two negative clusters in loop regions on the top of the sandwich, suggesting that KP-TerD may bind metal ions. Indeed, thermal denaturation experiments monitored by circular dichroism and NMR studies reveal that KP-TerD binds Ca(2+). Inductively coupled plasma-optical emission spectroscopy shows that the binding ratio of KP-TerD to Ca(2+) is 1:2. EDTA (ethylenediaminetetraacetic acid) titrations of Ca(2+)-saturated KP-TerD monitored by one-dimensional NMR yield estimated dissociation constants of 18  and 200 nM for the two Ca(2+)-binding sites of KP-TerD. NMR structures incorporating two Ca(2+) ions define a novel bipartite Ca(2)(+)-binding motif that is predicted to be highly conserved in TerD proteins. Moreover, these Ca(2+)-binding sites are also predicted to be present in two additional tellurite resistance proteins, TerE and TerZ. These results suggest that some form of Ca(2+) signaling plays a crucial role in tellurite resistance and in other responses of bacteria to multiple external stimuli that depend on the Ter genes. PMID:21112337

Pan, Yun-Ru; Lou, Yuan-Chao; Seven, Alpay B; Rizo, Josep; Chen, Chinpan

2011-02-01

279

CXCL1 Regulates Pulmonary Host Defense to Klebsiella Infection via CXCL2 , CXCL5, NF-?B and MAPKs  

PubMed Central

Pulmonary bacterial infections are a leading cause of death. Since the introduction of antibiotics, multidrug-resistant Klebsiella pneumoniae (Kp) became an escalating threat. Therefore, development of methods to augment antibacterial defense is warranted. Neutrophil recruitment is critical to clear bacteria and neutrophil migration in the lung requires the production of ELR+ CXC chemokines. Although lung specific CXCL1/KC transgene expression causes neutrophil-mediated clearance of Kp, the mechanisms underlying KC-mediated host defense against Kp have not been explored. Here we delineated the host defense functions of KC during pulmonary Kp infection using KC-/- mice. Our findings demonstrate that KC is important for expression of CXCL2/MIP-2 and CXCL5/LIX and activation of NF-?B, and MAPKs in the lung. Furthermore, KC-derived from both hematopoietic and resident cells contributes to host defense against Kp. Neutrophil depletion in mice prior to Kp infection reveals no differences in the production of MIP-2 and LIX or activation of NF-?B and MAPKs in the lung. Using murine bone marrow-derived (BMMs) and alveolar macrophages, we confirmed KC-mediated upregulation of MIP-2 and activation of NF-?B and MAPKs upon Kp infection. Moreover, neutralizing KC in BMMs prior to Kp challenge decreases bacteria-induced production of KC, MIP-2 and activation of NF-?B and MAPKs. These findings reveal the importance of KC produced by hematopoietic and resident cells in regulating pulmonary host defense against a bacterial pathogen via the activation of transcription factors and MAPKs as well as the expression of cell adhesion molecules and other neutrophil chemoattractants.

Cai, Shanshan; Batra, Sanjay; Lira, Sergio A.; Kolls, Jay K.; Jeyaseelan, Samithamby

2010-01-01

280

The crystal structures of Klebsiella pneumoniae acetolactate synthase with enzyme-bound cofactor and with an unusual intermediate.  

PubMed

Acetohydroxyacid synthase (AHAS) and acetolactate synthase (ALS) are thiamine diphosphate (ThDP)-dependent enzymes that catalyze the decarboxylation of pyruvate to give a cofactor-bound hydroxyethyl group, which is transferred to a second molecule of pyruvate to give 2-acetolactate. AHAS is found in plants, fungi, and bacteria, is involved in the biosynthesis of the branched-chain amino acids, and contains non-catalytic FAD. ALS is found only in some bacteria, is a catabolic enzyme required for the butanediol fermentation, and does not contain FAD. Here we report the 2.3-A crystal structure of Klebsiella pneumoniae ALS. The overall structure is similar to AHAS except for a groove that accommodates FAD in AHAS, which is filled with amino acid side chains in ALS. The ThDP cofactor has an unusual conformation that is unprecedented among the 26 known three-dimensional structures of nine ThDP-dependent enzymes, including AHAS. This conformation suggests a novel mechanism for ALS. A second structure, at 2.0 A, is described in which the enzyme is trapped halfway through the catalytic cycle so that it contains the hydroxyethyl intermediate bound to ThDP. The cofactor has a tricyclic structure that has not been observed previously in any ThDP-dependent enzyme, although similar structures are well known for free thiamine. This structure is consistent with our proposed mechanism and probably results from an intramolecular proton transfer within a tricyclic carbanion that is the true reaction intermediate. Modeling of the second molecule of pyruvate into the active site of the enzyme with the bound intermediate is consistent with the stereochemistry and specificity of ALS. PMID:14557277

Pang, Siew Siew; Duggleby, Ronald G; Schowen, Richard L; Guddat, Luke W

2004-01-16

281

Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia.  

PubMed

The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public. PMID:24820641

Ghaderpour, Aziz; Mohd Nasori, Khairul Nazrin; Chew, Li Lee; Chong, Ving Ching; Thong, Kwai Lin; Chai, Lay Ching

2014-06-15

282

Meropenem Resistance in Imipenem-Susceptible Meropenem-Resistant Klebsiella pneumoniae Isolates Not Detected by Rapid Automated Testing Systems  

PubMed Central

Klebsiella pneumoniae showing high resistance to all ?-lactams except imipenem, designated as ISMRK (imipenem-susceptible meropenem-resistant Klebsiella) is emerging in Japan. The carbapenem resistance of ISMRK cannot be screened by the Vitek and the RAISUS rapid automated susceptibility test systems, which may lead to inappropriate antimicrobial therapy, resulting in compromised patient outcomes.

Harino, Toshie; Kayama, Shizuo; Kuwahara, Ryuichi; Kashiyama, Seiya; Shigemoto, Norifumi; Onodera, Makoto; Yokozaki, Michiya; Ohge, Hiroki

2013-01-01

283

Factors associated with airway colonisation and invasion due to Klebsiella spp.  

PubMed

The clinical significance of a heavy growth of Klebsiella spp. in sputum was studied in 54 patients. All but 3 patients had significant factors potentially associated with respiratory tract colonisation or invasion. Risk factors identified for colonisation of the airway and for invasive disease were similar. Patients with community-acquired Klebsiella infections were more likely to have underlying chronic respiratory diseases. Prior antibiotic use was a risk factor for nosocomial infections which occurred more commonly with antibiotic-resistant organisms. The most common diagnoses were airway colonisation, acute community-acquired chest infections, and nosocomial chest infections. Primary acute community-acquired pneumonia was uncommon. The sensitivity and specificity of the sputum Gram stain (in the setting of positive sputum cultures) in suggesting the presence of invasive disease due to Klebsiella spp. were 42% and 69% respectively. PMID:8093134

Feldman, C; Smith, C; Kaka, S; de Jong, P; Goolam Mahomed, A; Frankel, A; Koornhof, H J

1993-09-01

284

CXCR1/CXCR2 Antagonism Is Effective in Pulmonary Defense against Klebsiella pneumoniae Infection  

PubMed Central

Klebsiella pneumoniae-associated pathology is largely mediated by neutrophilic inflammation. In this study, we administered Klebsiella pneumoniae to experimental guinea pig groups and the ELR-CXC chemokine antagonist CXCL8(3–72), ceftazidime, and dexamethasone to different groups, respectively. After 24?h, we assessed the animal's pulmonary inflammatory levels, including gross histopathology, airway neutrophilia, lung myeloperoxidase levels, expressions of CXCL8 and TNF, and airway bacterial loads. Compared with ceftazidime and dexamethasone treatments, the administration of the ELR-CXC chemokine antagonist CXCL8(3–72) alone was more effective than other methods, although it did not markedly attenuate the bacterial load. These results suggest new methods for the treatment of Klebsiella pneumoniae pathology.

Wei, Jing; Peng, Jing; Wang, Bing; Qu, Hong; Wang, Shiyi; Faisal, Aziz; Cheng, Jia-Wei; Gordon, John R.; Li, Fang

2013-01-01

285

The emergence of Klebsiella pneumoniae endogenous endophthalmitis in the USA: basic and clinical advances.  

PubMed

Endogenous endophthalmitis (EE) is a rare but devastating infection that occurs secondary to seeding of the intraocular cavity from an extraocular focus. Recent reports suggest the increasing prevalence and incidence of Klebsiella pneumoniae as a causative organism in Asian countries. Analysis of the largest cohorts published to date suggests that K. pneumoniae endogenous endophthalmitis (KPEE) is 10 to 15 times more prevalent than other causes of EE. The incidence of KPEE among patients with systemic Klebsiella infection appears to be >100-fold more common than other causes of EE. The exact reason for these observations is not clear, but a number of studies now suggest that Klebsiella serotypes K1 and K2 have virulence factors that enhance their survival in diabetic patients and increase their pathogenicity. Here, we report two cases of KPEE in the USA. We also review the recent clinical and basic science literature on the prevalence, incidence, and pathophysiology of this emerging and devastating infection. PMID:23514342

Kashani, Amir H; Eliott, Dean

2013-01-01

286

Klebsiella serotype-13 capsular polysaccharide: primary structure and depolymerization by a bacteriophage-borne glycanase.  

PubMed

Periodate oxidation and Smith degradation, methylation analysis including uronic acid degradation, partial hydrolysis with acid, bacteriophage degradation, and p.m.r. spectroscopy have been used to elucidate the primary structure of the Klebsiella serotype-13 capsular polysaccharide. The polymer consists of pentasaccharide repeating-units comprising a 4)-beta-D-Manp-(1 leads to 4)-alpha-D-Glcp-(1 leads to 3)-beta-D-Glcp-(1 leads to chain with a 3,4-O-(1-carboxyethylidene)-beta-D-Galp-(1 leads to 4)-alpha-D-GlcAp-(1 leads to branch at position 3 of the mannose. It is shown that there is a glycanase activity associated with particles of Klebsiella bacteriophage No. 13, which catalyses hydrolysis of chain beta-D-Glcp-(1 leads to 4)-beta-D-Manp linkages in the type-13 polysaccharide. The chemical basis of some serological cross-reactions of the Klebsiella K13 antigen is discussed. PMID:589608

Niemann, H; Frank, N; Stirm, S

1977-11-01

287

Klebsiella pneumoniae induces an inflammatory response in an in vitro model of blood-retinal barrier.  

PubMed

Klebsiella pneumoniae has become an important pathogen in recent years. Although most cases of K. pneumoniae endogenous endophthalmitis occur via hematogenous spread, it is not yet clear which microbial and host factors are responsible for the ability of K. pneumoniae to cross the blood-retinal barrier (BRB). In the present study, we show that in an in vitro model of BRB based on coculturing primary bovine retinal endothelial cells (BREC) and primary bovine retinal pericytes (BRPC), K. pneumoniae infection determines changes of transendothelial electrical resistance (TEER) and permeability to sodium fluorescein. In the coculture model, bacteria are able to stimulate the enzyme activities of endothelial cytosolic and Ca(2+)-independent phospholipase A2s (cPLA2 and iPLA2). These results were confirmed by the incremental expression of cPLA2, iPLA2, cyclo-oxygenase-1 (COX1), and COX2 in BREC, as well as by cPLA2 phosphorylation. In supernatants of K. pneumoniae-stimulated cocultures, increases in prostaglandin E2 (PGE2), interleukin-6 (IL-6), IL-8, and vascular endothelial growth factor (VEGF) production were found. Incubation with K. pneumoniae in the presence of arachidonoyl trifluoromethyl ketone (AACOCF3) or bromoenol lactone (BEL) caused decreased PGE2 and VEGF release. Scanning electron microscopy and transmission electron microscopy images of BREC and BRPC showed adhesion of K. pneumoniae to the cells, but no invasion occurred. K. pneumoniae infection also produced reductions in pericyte numbers; transfection of BREC cocultured with BRPC and of human retinal endothelial cells (HREC) cocultured with human retinal pericytes (HRPC) with small interfering RNAs (siRNAs) targeted to cPLA2 and iPLA2 restored the pericyte numbers and the TEER and permeability values. Our results show the proinflammatory effect of K. pneumoniae on BREC, suggest a possible mechanism by which BREC and BRPC react to the K. pneumoniae infection, and may provide physicians and patients with new ways of fighting blinding diseases. PMID:24478098

Motta, C; Salmeri, M; Anfuso, C D; Amodeo, A; Scalia, M; Toscano, M A; Giurdanella, G; Alberghina, M; Lupo, G

2014-02-01

288

Hypermucoviscosity as a Virulence Factor in Experimental Klebsiella pneumoniae Endophthalmitis  

PubMed Central

Purpose Klebsiella pneumoniae is a common cause of endogenous bacterial endophthalmitis, a disease that frequently results in a poor visual outcome. Hypermucoviscosity has been identified as a virulence factor among clinical bacteremia isolates of K. pneumoniae. In this study, we established an experimental murine model of K. pneumoniae endophthalmitis and analyzed the role of hypermucoviscosity in pathogenesis. Methods C57BL/6J mice were intravitreally injected with 100 CFU of hypermucoviscous (HMV+) or non-hypermucoviscous (HMV?) K. pneumoniae. Intraocular bacterial growth, retinal function, gross pathology, and inflammatory responses were monitored every 3 h until the eyes lost significant (>90%) retinal function or appeared to clear the infection. Results The HMV+ strain grew logarithmically in eyes until approximately 15 h postinfection, reaching a stationary phase of growth at approximately 8.0 log10 CFU/eye. The HMV? strain grew logarithmically to approximately 7.6 log10 by 18 h, but bacterial numbers declined to approximately 6.4 log10 CFU/eye by 21 h postinfection. Eyes infected with the HMV+ strain retained approximately 35% A-wave and <10% B-wave function by 18 h postinfection. These eyes also had a cumulative clinical score of 14+ by 18 h and underwent phthisis between 21–24 h. Eyes infected with the HMV? strain had a cumulative clinical score of <6 and retained >60% A-wave and >50% B-wave function throughout 21 h. Five of 7 eyes had <100 CFU HMV? K. pneumoniae at 27 h postinfection. Conclusions Our findings demonstrate the site-threatening consequences of K. pneumoniae endophthalmitis and the importance of the hypermucoviscosity phenotype in the pathogenesis of experimental K. pneumoniae endophthalmitis.

Wiskur, B.J.; Hunt, J.J.; Callegan, M.C.

2008-01-01

289

Epidemic Klebsiella pneumoniae ST258 Is a Hybrid Strain  

PubMed Central

ABSTRACT Carbapenem-resistant Enterobacteriaceae (CRE), especially Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae, pose an urgent threat in health facilities in the United States and worldwide. K. pneumoniae isolates classified as sequence type 258 (ST258) by multilocus sequence typing are largely responsible for the global spread of KPC. A recent comparative genome study revealed that ST258 K. pneumoniae strains are two distinct genetic clades; however, the molecular origin of ST258 largely remains unknown, and our understanding of the evolution of the two genetic clades is incomplete. Here we compared the genetic structures and single-nucleotide polymorphism (SNP) distributions in the core genomes of strains from two ST258 clades and other STs (ST11, ST442, and ST42). We identified an ~1.1-Mbp region on ST258 genomes that is homogeneous to that of ST442, while the rest of the ST258 genome resembles that of ST11. Our results suggest ST258 is a hybrid clone—80% of the genome originated from ST11-like strains and 20% from ST442-like strains. Meanwhile, we sequenced an ST42 strain that carries the same K-antigen-encoding capsule polysaccharide biosynthesis gene (cps) region as ST258 clade I strains. Comparison of the cps-harboring regions between the ST42 and ST258 strains (clades I and II) suggests the ST258 clade I strains evolved from a clade II strain as a result of cps region replacement. Our findings unravel the molecular evolution history of ST258 strains, an important first step toward the development of diagnostic, therapeutic, and vaccine strategies to combat infections caused by multidrug-resistant K. pneumoniae.

Chen, Liang; Mathema, Barun; Pitout, Johann D. D.; DeLeo, Frank R.

2014-01-01

290

Synthesis of Fe3O4 poly(styrene-glycidyl methacrylate) magnetic porous microspheres and application in the immobilization of Klebsiella sp. FD-3 to reduce Fe(III)EDTA in a NO(x) scrubbing solution.  

PubMed

Magnetic poly(styrene-glycidyl methacrylate) porous microspheres (MPPM) with high magnetic contents were prepared by surfactant reverse micelles and emulsion polymerization of monomers, in which the well-dispersed Fe(3)O(4) nanoparticles were modified by polyethylene glycol (PEG) and oleic acid (OA) respectively. The characterizations showed that both of the OA-MPPM and the PEG-MPPM were ferromagnetic, however, the OA-MPPM was used to immobilize the bacteria for more advantages. Therefore, the effects of monomer ratio, surfactant, crosslinker and amount of Fe(3)O(4) on the structure, morphology and magnetic contents of the OA-MPPM were investigated. Then, the OA-MPPM was utilized to immobilize Klebsiella sp. FD-3, an iron-reducing bacterium for Fe(III)EDTA reduction applied in NO(x) removal. Compared with free bacteria, the immobilized FD-3 showed a better tolerance to the unbeneficial pH and temperature conditions. PMID:23334160

Wang, Xiaoyan; Zhou, Zuoming; Jing, Guohua

2013-02-01

291

Genome Sequences of Two Carbapenemase-Resistant Klebsiella pneumoniae ST258 Isolates  

PubMed Central

Klebsiella pneumoniae, an ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogen, has acquired multiple antibiotic resistance genes and is becoming a serious public health threat. Here, we report the genome sequences of two representative strains of K. pneumoniae from the emerging K. pneumoniae carbapenemase (KPC) outbreak in northeast Ohio belonging to sequence type 258 (ST258) (isolates Kb140 and Kb677, which were isolated from blood and urine, respectively). Both isolates harbor a blaKPC gene, and strain Kb140 carries blaKPC-2, while Kb677 carries blaKPC-3.

Ramirez, Maria Soledad; Xie, Gang; Johnson, Shannon; Davenport, Karen; van Duin, David; Perez, Federico; Bonomo, Robert A.; Chain, Patrick

2014-01-01

292

Preliminary examinations on the enterotoxigenicity of isolates of Klebsiella pneumoniae from seafoods.  

PubMed

One hundred and eighty-five seafood samples, consisting of 96 freshwater fish, 37 marine fish, 13 freshwater prawn, 13 marine prawn and 26 molluscs were screened for presence of Klebsiella. Out of these, 12 isolates of Klebsiella were identified, Four K. pneumoniae var. ozaenae were isolated from marine fish samples and eight K. pneumoniae var. pneumoniae, six from freshwater fish and two from freshwater prawns. All 12 isolates were tested for enterotoxigenicity by the vasopermeability factor test in rabbits, the mouse foot pad test, the latex agglutination test and the coagglutination test. One isolate of K. pneumoniae var pneumoniae, isolated from fresh water prawn was found enterotoxigenic. PMID:1457293

Singh, B R; Kulshreshtha, S B

1992-08-01

293

Structural investigation of the capsular polysaccharide of Klebsiella serotype K12.  

PubMed

Klebsiella K12 capsular polysaccharide has been investigated by the techniques of methylation, Smith degradation-periodate oxidation, uronic acid degradation, and partial hydrolysis, in conjunction with 1H-n.m.r. spectroscopy at 100 and 220 MHz, and 13C-n.m.r. spectroscopy at 20 MHz. The structure has been found to consist of the hexasaccharide repeating-unit shown, having a D-galactofuranosyl residue at the branch point. In this series, a D-galactofuranosyl residue has previously only been found in the polysaccharide from Klebsiella K41. PMID:7407803

Dutton, G G; Savage, A V

1980-08-15

294

Diversity of plasmids responsible for multiple resistance in Klebsiella serotype K2.  

PubMed

Klebsiella of capsular type K2 were investigated to find out whether a single epidemic clone was the source of many outbreaks of infection in different hospitals, in different areas over a period of five years. The klebsiellas studied were found to be very similar; they were of the same biotype, had similar klebecin sensitivity patterns and carried multiple drug-resistance plasmids; however, characterization of these plasmids showed that they were heterogeneous. Thus there was not a single epidemic bacterial clone. PMID:7462603

Richards, H; Hughes, V; Datta, N

1981-04-01

295

A structural investigation of the capsular polysaccharide of Klebsiella K14.  

PubMed

The structure of the capsular polysaccharide isolated from Klebsiella serotype K14 has been investigated employing a combination of chemical and spectroscopic methods. The repeating structure is shown to be of the "4 + 1 + 1" type, and it carries a 1-carboxyethylidene acetal substituent at positions 4 and 6 of a terminal glucose residue. The polysaccharide is one of a group of only three Klebsiella polysaccharides that have been found to contain a galactofuranose residue in the repeating unit. The repeating unit has the following structure: (Formula: see text). PMID:4053100

Dutton, G G; Parolis, H; Parolis, L A

1985-07-15

296

Genome Sequences of Two Carbapenemase-Resistant Klebsiella pneumoniae ST258 Isolates.  

PubMed

Klebsiella pneumoniae, an ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogen, has acquired multiple antibiotic resistance genes and is becoming a serious public health threat. Here, we report the genome sequences of two representative strains of K. pneumoniae from the emerging K. pneumoniae carbapenemase (KPC) outbreak in northeast Ohio belonging to sequence type 258 (ST258) (isolates Kb140 and Kb677, which were isolated from blood and urine, respectively). Both isolates harbor a blaKPC gene, and strain Kb140 carries blaKPC-2, while Kb677 carries blaKPC-3. PMID:24948759

Ramirez, Maria Soledad; Xie, Gang; Johnson, Shannon; Davenport, Karen; van Duin, David; Perez, Federico; Bonomo, Robert A; Chain, Patrick; Tolmasky, Marcelo E

2014-01-01

297

Chlorine resistance patterns of bacteria from two drinking water distribution systems.  

PubMed Central

The relative chlorine sensitivities of bacteria isolated from chlorinated and unchlorinated drinking water distribution systems were compared by two independent methods. One method measured the toxic effect of free chlorine on bacteria, whereas the other measured the effect of combined chlorine. Bacteria from the chlorinated system were more resistant to both the combined and free forms of chlorine than those from the unchlorinated system, suggesting that there may be selection for more chlorine-tolerant microorganisms in chlorinated waters. Bacteria retained on the surfaces of 2.0-microns Nuclepore membrane filters were significantly more resistant to free chlorine compared to the total microbial population recovered on 0.2-micron membrane filters, presumably because aggregated cells or bacteria attached to suspended particulate matter exhibit more resistance than unassociated microorganisms. In accordance with this hypothesis, scanning electron microscopy of suspended particulate matter from the water samples revealed the presence of attached bacteria. The most resistant microorganisms were able to survive a 2-min exposure to 10 mg of free chlorine per liter. These included gram-positive spore-forming bacilli, actinomycetes, and some micrococci. The most sensitive bacteria were readily killed by chlorine concentrations of 1.0 mg liter-1 or less, and included most gram-positive micrococci, Corynebacterium/Arthrobacter, Klebsiella, Pseudomonas/Alcaligenes, Flavobacterium/Moraxella, and Acinetobacter. Images

Ridgway, H F; Olson, B H

1982-01-01

298

Factors promoting survival of bacteria in chlorinated water supplies.  

PubMed Central

Results of our experiments showed that the attachment of bacteria to surfaces provided the greatest increase in disinfection resistance. Attachment of unencapsulated Klebsiella pneumoniae grown in medium with high levels of nutrients to glass microscope slides afforded the microorganisms as much as a 150-fold increase in disinfection resistance. Other mechanisms which increased disinfection resistance included the age of the biofilm, bacterial encapsulation, and previous growth conditions (e.g., growth medium and growth temperature). These factors increased resistance to chlorine from 2- to 10-fold. The choice of disinfectant residual was shown to influence the type of resistance mechanism observed. Disinfection by free chlorine was affected by surfaces, age of the biofilm, encapsulation, and nutrient effects. Disinfection by monochloramine, however, was only affected by surfaces. Importantly, results showed that these resistance mechanisms were multiplicative (i.e., the resistance provided by one mechanism could be multiplied by the resistance provided by a second mechanism).

LeChevallier, M W; Cawthon, C D; Lee, R G

1988-01-01

299

Bacteria fauna from the house fly, Musca domestica (L.).  

PubMed

The house fly, Musca domestica has long been considered a potential agent for disease transmission ever since its existence. The general truth of this assertion remains undisputed till the present day in spite of increasing awareness toward an improved sanitation and better hygiene. The habitual movement of house fly from filthy substrata such as human faeces, animal excreta, carcasses, garbage, etc. makes them ideal candidates for disease transmission such as cholera, shigellosis, salmonellosis and others when settling on food. Fly as a potential mechanical vector of pathogenic bacteria was elucidated in this study by examining flies from various breeding sites such as food courts, dumping ground, food processing areas and poultry farm in Peninsular Malaysia. The flies were baited with 10% sugar solution on a glass slide in the field. All materials used for collection of samples were sterile. Bacteria from fly sample were isolated using the normal isolation technique. Bacillus sp., Coccobacillus sp., Staphylococcus sp., Microccus sp., Streptococcus sp., Acinetobacter sp., Enterobacter sp., Proteus sp., Escherichia sp., Klebsiella sp. and yeast cells were isolated from feaces, vomitus, external surfaces and internal organs of house fly. Newly emerged house fly did not harbour any bacteria. PMID:16883292

Nazni, W A; Seleena, B; Lee, H L; Jeffery, J; T Rogayah, T A R; Sofian, M A

2005-12-01

300

Immunogenic properties of Klebsiella pneumoniae type 2 capsular polysaccharide.  

PubMed Central

The immunoprotective activity of Klebsiella pneumoniae K2 cell surface preparations and purified capsular polysaccharide was tested in mice. The 50% protective dose (PD50), expressed as capsular polysaccharide content, was 2 ng for cell surface preparations and 50 ng for purified capsular polysaccharide. Both preparations lost their immunoprotective activity after alkali treatment. Immune sera were raised in rabbits immunized with cell surface preparations. The precipitating and hemagglutinating capacity of these antisera was tested against either purified capsular polysaccharide or alkali-treated capsular polysaccharide. No difference was observed between the reactivity of the antisera against each antigen. The protective activity of these sera was tested on mice in passive transfer experiments, before and after absorption with either purified capsular polysaccharide or alkali-treated capsular polysaccharide. The sera lost their protective activity after absorption with purified capsular polysaccharide and after absorption with alkali-treated capsular polysaccharide. These experiments show that the difference in immunoprotective activity of cell surface preparations, purified capsular polysaccharide, and alkali-treated capsular polysaccharide is not due to a difference in their antigenic determinants. Cell surface preparations and purified capsular polysaccharide were fractionated by gel filtration on Sepharose 4B and by ultracentrifugation on cesium chloride density gradients. Three forms of capsular polysaccharide have been characterized. (i) A form of capsular polysaccharide with a very high protective activity (PD50 = 2 ng) that copurified with protein and lipopolysaccharide and was characterized by a low coefficient of distribution (Kd = 0.20) and a low density (1.5 to 1.6 g/cm3). (ii) A form of capsular polysaccharide with an intermediate protective activity (PD50 = 50 ng), contamined by less than 3% protein and 1% lipopolysaccharide, with a Kd of 0.35, and a density of 1.7 to 1.8 g/cm3. (iii) A nonimmunoprotective capsular polysaccharide obtained after alkali treatment of either cell surface preparations or purified capsular polysaccharide. The Kd of these fractions varied from 0.20 to 0.90 and their density from 1.7 to 1.8 g/cm3.

Robert, A; Jouin, H; Fournier, J M

1986-01-01

301

Genomics of Probiotic Bacteria  

NASA Astrophysics Data System (ADS)

Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

302

Species Numbers in Bacteria  

PubMed Central

A modified biological species definition (BSD), i.e., that bacteria exchange genes within a species, but not usually between species, is shown to apply to bacteria. The formal definition of bacterial species, which is more conservative than the modified BSD, is framed in terms of DNA hybridization. From this I estimate there are a million species of bacteria in 30 grams of rich forest topsoil and propose that there will be at least a billion species worldwide.

Dykhuizen, Daniel

2010-01-01

303

Genome size in bacteria  

Microsoft Academic Search

This manuscript examines genome size in bacteria. The opposing capability of bacteria to alter their genome sizes and order\\u000a of genes within limits yet remain somewhat constant provides a mechanism for diversity and evolution in bacterial populations.\\u000a Bacteria may have evolved by increasing their genome size and changing gene orders with the assistance of restriction endonucleases\\u000a cleaving foreign DNA and

J. T. Trevors

1996-01-01

304

Bacteria and lignin degradation  

Microsoft Academic Search

Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material. It is degraded and\\u000a modified by bacteria in the natural world, and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.\\u000a Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling, erosion, and cavitation. With the advantages\\u000a of immense environmental

Jing Li; Hongli Yuan; Jinshui Yang

2009-01-01

305

Metallization of bacteria cells  

Microsoft Academic Search

Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically\\u000a conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique\\u000a of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been

Xiangfeng Li; Yaqin Li; Jun Cai; Deyuan Zhang

2003-01-01

306

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2009 and March 2010].  

PubMed

Bacteria isolated from surgical infections during the period from April 2009 to March 2010 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 671 strains including 16 strains of Candida spp. were isolated from 174 (79.1%) of 220 patients with surgical infections. Four hundred and eleven strains were isolated from primary infections, and 244 strains were isolated from surgical site infection. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from surgical site infection aerobic Gram-positive bacteria were predominant, followed by anaerobic Gram-negative bacteria. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was highest, followed by Streptococcus spp., and Staphylococcus spp. in this order, from primary infections, while Enterococcus spp. was highest, followed by Staphylococcus spp. from surgical site infection. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa, in this order, and from surgical site infection, E. coli was most predominantly isolated, followed by P. aeruginosa and E. cloacae. Among anaerobic Gram-positive bacteria, the isolation rate of Eggerthella lenta was the highest from primary infections, followed by Parvimonas micra, Streptococcus constellatus and Finegoldia magna, and from surgical site infection, E. lenta was most predominantly isolated. Among anaerobic Gram-negative bacteria, the isolation rate of Bilophila wadsworthia was the highest from primary infections, followed by Bacteroides fragilis, Bacteroides ovatus and Bacteroides thetaiotaomicron, and from surgical site infection, B. fragilis was most predominantly isolated, followed by B. ovatus, B. wadsworthia and B. thetaiotaomicron, in this order. In this series, we noticed no vancomycin-resistant Gram-positive cocci, nor multidrug-resistant P. aeruginosa. We should carefully follow up B. wadsworthia which was resistant to various antibiotics, and also Bacteroides spp. which was resistant to many beta-lactam antibiotics. PMID:21861307

Shinagawa, Nagao; Osanai, Hiroyuki; Hirata, Koichi; Furuhata, Tomohisa; Mizukuchi, Tohru; Yanai, Yoshiyuki; Hata, Fumitake; Taniguchi, Masaaki; Sasaki, Kazuaki; Someya, Tetsufumi; Sasaki, Kazunori; Oono, Keisuke; Mizuno, Isamu; Shamoto, Tomoya; Fukui, Takuji; Tokita, Shoji; Nakamura, Masashi; Mashita, Keiji; Shibuya, Hitoshi; Tanaka, Moritsugu; Hasegawa, Itaru; Kimura, Masami; Oshima, Hideki; Maeda, Hideki; Ishikawa, Syu; Mukaiya, Mitsuhiro; Kihara, Chikasi; Mizuno, Akira; Watabe, Kosho; Iwai, Akihiko; Saito, Takaaki; Hoshikawa, Tsuyoshi; Kimura, Hitoshi; Moori, Noriaki; Sumita, Naoki; Jae-Hoon, Yoo; Kubo, Shoji; Lee, Shigeru; Aikawa, Naoki; Sekine, Kazuhiko; Abe, Shinya; Oomura, Toru; Takeyama, Hiromitsu; Wakasugi, Takehiro; Kobayashi, Yasuhito; Tsuji, Takeshi; Yamaue, Hiroki; Ozawa, Satoru; Takesue, Yoshio; Fujiwara, Toshiyoshi; Tsumura, Hiroaki; Kimura, Hideyuki; Yokoyama, Takashi; Iwagaki, Hiromi; Takeuchi, Hitoshi; Tanakaya, Kouji; Sueda, Taijiro; Hiyama, Eiso; Murakami, Yoshiaki; Ohge, Hiroki; Uemura, Kenichiro; Yasunami, Yoichi; Sasaki, Takamitsu

2011-06-01

307

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents --special references to bacteria isolated between April 2008 and March 2009].  

PubMed

Bacteria isolated from infections in abdominal surgery during the period from April 2008 to March 2009 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 712 strains including 18 strains of Candida spp. were isolated from 173 (80.5%) of 215 patients with surgical infections. Three hundred and sixty-six strains were isolated from primary infections, and 346 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from postoperative infections aerobic Gram-positive bacteria were predominant, followed by anaerobic Gram-negative bacteria. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was highest, followed by Streptococcus spp., and Staphylococcus spp. in this order, from primary infections, while Enterococcus spp. was highest, followed by Staphylococcus spp. from postoperative infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa, in this order, and from postoperative infections, P aeruginosa was most predominantly isolated, followed by E. coli, Enterobacter cloacae, and K. pneumoniae. Among anaerobic Gram-positive bacteria, the isolation rate of Eggerthella lenta was the highest from primary infections, followed by Parvimonas micra, Streptococcus constellatus and Gemella morbillorum, and from postoperative infections, E. lenta was most predominantly isolated. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis was the highest from primary infections, followed by Bacteroides thetaiotaomicron, Bacteroides ovatus and Bilophila wadsworthia, and from postoperative infections, B. fragilis was most predominantly isolated, followed by B. thetaiotaomicron, B. wadsworthia and B. ovatus, in this order. In this series, we noticed no vancomycin-resistant methicillin-resistant S. aureus, and Enterococcus spp., nor multidrug-resistant P aeruginosa. We should carefully follow up B. wadsworthia which was resistant to various antibiotics, and also Bacteroides spp. which was resistant to many beta-lactam antibiotics. PMID:20919496

Shinagawa, Nagao; Hasegawa, Masamitsu; Hirata, Koichi; Furuhata, Tomohisa; Mizukuchi, Tohru; Osanai, Hiroyuki; Yanai, Yoshiyuki; Hata, Fumitaka; Sasaki, Kazuaki; Someya, Tetsufumi; Harada, Keisuke; Oono, Keisuke; Tokita, Shoji; Nakamura, Masashi; Shibuya, Hitoshi; Hasegawa, Itaru; Kimura, Masami; Oshima, Hideki; Maeda, Hideki; Mukaiya, Mitsuhiro; Kihara, Chikasi; Kosho, Watabe; Hoshikawa, Tsuyoshi; Kimura, Hitoshi; Ushijima, Yasuhide; Yae-Hoon, Yoo; Aikawa, Naoki; Abe, Shinya; Yura, Jiro; Takeyama, Hiromitsu; Wakasugi, Takehiro; Taniguchi, Masaaki; Mizuno, Isamu; Fukui, Takuji; Mashita, Keiji; Ishikawa, Svu; Mizuno, Akira; Moori, Noriaki; Sumita, Naoki; Kubo, Shoji; Lee, Shigeruj; Oomura, Toru; Kobayashi, Yasuhito; Tsuji, Takeshi; Yamaue, Hiroki; Kawai, Manabu; Takesue, Yoshio; Tanaka, Noriaki; Kimura, Hideyuki; Iwagaki, Hiromi; Sueda, Taijiro; Hiyama, Eiso; Murakami, Yoshiaki; Ooge, Hiroki; Uemura, Kenichiro; Tsumura, Hiroaki; Yokoyama, Takashi; Takeuchi, Hitoshi; Tanakaya, Kouji; Yasunami, Yoichi; Ryu, Shinichiro

2010-04-01

308

Influence of Inoculum Size and Marbofloxacin Plasma Exposure on the Amplification of Resistant Subpopulations of Klebsiella pneumoniae in a Rat Lung Infection Model?  

PubMed Central

We tested the hypothesis that the bacterial load at the infection site could impact considerably on the pharmacokinetic/pharmacodynamic (PK/PD) parameters of fluoroquinolones. Using a rat lung infection model, we measured the influence of different marbofloxacin dosage regimens on selection of resistant bacteria after infection with a low (105 CFU) or a high (109 CFU) inoculum of Klebsiella pneumoniae. For daily fractionated doses of marbofloxacin, prevention of resistance occurred for an area-under-the-concentration-time-curve (AUC)/MIC ratio of 189 h for the low inoculum, whereas for the high inoculum, resistant-subpopulation enrichment occurred for AUC/MIC ratios up to 756 h. For the high-inoculum-infected rats, the AUC/MIC ratio, Cmax/MIC ratio, and time within the mutant selection window (TMSW) were not found to be effective predictors of resistance prevention upon comparison of fractionated and single administrations. An index corresponding to the ratio of the time that the drug concentrations were above the mutant prevention concentration (MPC) over the time that the drug concentrations were within the MSW (T>MPC/TMSW) was the best predictor of the emergence of resistance: a T>MPC/TMSW ratio of 0.54 was associated with prevention of resistance for both fractionated and single administrations. These results suggest that the enrichment of resistant bacteria depends heavily on the inoculum size at the start of an antimicrobial treatment and that classical PK/PD parameters cannot adequately describe the impact of different dosage regimens on enrichment of resistant bacteria. We propose an original index, the T>MPC/TMSW ratio, which reflects the ratio of the time that the less susceptible bacterial subpopulation is killed over the time that it is selected, as a potentially powerful indicator of prevention of enrichment of resistant bacteria. This ratio is valid only if plasma concentrations achieve the MPC.

Kesteman, Anne-Sylvie; Ferran, Aude A.; Perrin-Guyomard, Agnes; Laurentie, Michel; Sanders, Pascal; Toutain, Pierre-Louis; Bousquet-Melou, Alain

2009-01-01

309

Cerebellar abscess and meningitis, caused by Shewanella putrefaciens and Klebsiella pneumoniae, associated with chronic otitis media.  

PubMed

Shewanella putrefaciens is a facultatively anaerobic, non-motile, Gram-negative, non-fermentative bacterium. It is found in various environments and has been isolated worldwide. S. putrefaciens is a rare cause of brain abscesses and meningitis. This is a case report of a cerebellar abscess and meningitis caused by Shewanella putrefaciens and Klebsiella pneumoniae in a river trap fisherman. PMID:17965359

Yilmaz, Gurdal; Aydin, Kemalettin; Bektas, Devrim; Caylan, Rahmet; Caylan, Refik; Koksal, Iftihar

2007-11-01

310

Yersiniabactin Is a Virulence Factor for Klebsiella pneumoniae during Pulmonary Infection  

Microsoft Academic Search

Iron acquisition systems are essential for the in vivo growth of bacterial pathogens. Despite the epidemio- logical importance of Klebsiella pneumoniae, few experiments have examined the importance of siderophores in the pathogenesis of this species. A previously reported signature-tagged mutagenesis screen identified an attenuated strain that featured an insertional disruption in ybtQ, which encodes a transporter for the sid- erophore

Matthew S. Lawlor; Christopher O'Connor; Virginia L. Miller

2007-01-01

311

Effect of Amino Acids on the Nitrogenase System of Klebsiella Pneumoniae.  

National Technical Information Service (NTIS)

The effect of exogenous amino acids and the free amino acid pool on the synthesis of the nitrogenase system of Klebsiella pneumoniae M5al (formerly Aerobacter aerogenes M5al) was investigated. When an actively N2-fixing culture was used to inoculate a med...

D. C. Yoch R. M. Pengra

1966-01-01

312

Induction by Klebsiella aerogenes of a Melanin-Like Pigment in Cryptococcus neoformans  

Microsoft Academic Search

While studying the interaction of Cryptococcus neoformans with Dictyostelium discoideum, we noticed that yeast colonies in agar with a feeder lawn of Klebsiella aerogenes were brown. This finding was intriguing because C. neoformans colonies are not pigmented unless they are provided with precursors for melanization. Strains of all C. neoformans serotypes produced brown pigment in response to K. aerogenes at

Susana Frases; Stuart Chaskes; Ekaterina Dadachova; Arturo Casadevall

2006-01-01

313

Klebsiella pneumoniae Strains Producing Extended-Spectrum ?-Lactamases in Spain: Microbiological and Clinical Features?  

PubMed Central

Extended-spectrum ?-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use.

de Alegria, C. Ruiz; Rodriguez-Bano, J.; Cano, M. E.; Hernandez-Bello, J. R.; Calvo, J.; Roman, E.; Diaz, M. A.; Pascual, A.; Martinez-Martinez, L.

2011-01-01

314

Familial Spread of a Virulent Clone of Klebsiella pneumoniae Causing Primary Liver Abscess?  

PubMed Central

Capsule-forming Klebsiella pneumoniae K1 caused primary liver abscess in two household members of a family. The causative isolates had identical pulsed-field gel electrophoresis patterns and were determined to be sequence type 23. An additional member of the family was found to carry the same strain without clinical manifestation.

Harada, Sohei; Tateda, Kazuhiro; Mitsui, Hiroshi; Hattori, Yusuke; Okubo, Masao; Kimura, Sei; Sekigawa, Kenichiro; Kobayashi, Katsuya; Hashimoto, Naoaki; Itoyama, Satoru; Nakai, Tatsuro; Suzuki, Takeo; Ishii, Yoshikazu; Yamaguchi, Keizo

2011-01-01

315

Plasmid-Mediated KPC-2 in a Klebsiella pneumoniae Isolate from China?  

PubMed Central

A carbapenem-resistant isolate of Klebsiella pneumoniae producing class A carbapenemase KPC-2 was identified in Zhejiang, China. The KPC-2 gene was located on an approximately 60-kb plasmid in a genetic environment partially different from that of blaKPC-2 in the isolates from the United States and Colombia.

Wei, Ze-Qing; Du, Xiao-Xing; Yu, Yun-Song; Shen, Ping; Chen, Ya-Gang; Li, Lan-Juan

2007-01-01

316

Immunoprophylaxis against klebsiella and pseudomonas aeruginosa infections. The Federal Hyperimmune Immunoglobulin Trial Study Group.  

PubMed

To determine if passive immunization could decrease the incidence or severity of Klebsiella and Pseudomonas aeruginosa infections, patients admitted to intensive care units of 16 Department of Veterans Affairs and Department of Defense hospitals were randomized to receive either 100 mg/kg intravenous hyperimmune globulin (IVIG), derived from donors immunized with a 24-valent Klebsiella capsular polysaccharide plus an 8-valent P. aeruginosa O-polysaccharide-toxin A conjugate vaccine, or an albumin placebo. The overall incidence and severity of vaccine-specific Klebsiella plus Pseudomonas infections were not significantly different between the groups receiving albumin and IVIG. There was some evidence that IVIG may decrease the incidence (2.7% albumin vs. 1.2% IVIG) and severity (1.0% vs. 0.3%) of vaccine-specific Klebsiella infections, but these reductions were not statistically significant. The trial was stopped because it was statistically unlikely that IVIG would be protective against Pseudomonas infections at the dosage being used. Patients receiving IVIG had more adverse reactions (14.4% vs. 9.2%). PMID:8769611

Donta, S T; Peduzzi, P; Cross, A S; Sadoff, J; Haakenson, C; Cryz, S J; Kauffman, C; Bradley, S; Gafford, G; Elliston, D; Beam, T R; John, J F; Ribner, B; Cantey, R; Welsh, C H; Ellison, R T; Young, E J; Hamill, R J; Leaf, H; Schein, R M; Mulligan, M; Johnson, C; Abrutyn, E; Griffiss, J M; Slagle, D

1996-09-01

317

Production and purification of rhamnose from microbial polysaccharide produced by Klebsiella sp. I-714  

Microsoft Academic Search

A rhamnose-containing microbial polysaccharide has been produced by Klebsiella sp. I-714. strain. The polysaccharide has been used as a source for the obtention of L-rhamnose. A biotechnological process has been developed to purify the hydrolyzed polysaccharide (EPSH), which contains rhamnose, galactose and glucuronic acid.

J. M. Serrat; G. Caminal; F. Gòdia; C. Solà; J. López-Santin

1995-01-01

318

Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features.  

PubMed

Extended-spectrum ?-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use. PMID:21191059

Ruiz de Alegría, C; Rodríguez-Baño, J; Cano, M E; Hernández-Bello, J R; Calvo, J; Román, E; Díaz, M A; Pascual, A; Martínez-Martínez, L

2011-03-01

319

Consequences of Reduction of Klebsiella pneumoniae Capsule Expression on Interactions of This Bacterium with Epithelial Cells  

Microsoft Academic Search

Most Klebsiella pneumoniae clinical isolates are fully encapsulated and adhere in vitro to intestinal cell lines with an aggregative pattern. In this study, the influence of the capsule on interactions with epithelial cells was investigated by creating an isogenic mutant defective in the synthesis of the capsule. Determination of the uronic acid content of bacterial extracts confirmed that the mutant

SABINE FAVRE-BONTE; BERNARD JOLY; CHRISTIANE FORESTIER

320

An evaluation of multiple phenotypic screening methods for Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae.  

PubMed

Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae may display MICs to carbapenems within susceptible or intermediate ranges, prompting confirmatory testing. Four phenotypic methods to detect KPC producers were evaluated against a collection of clinical Enterobacteriaceae isolates. Meropenem-phenylboronic acid double disk synergy testing demonstrated the best performance with 100% sensitivity and specificity. PMID:24674388

Hirsch, Elizabeth B; Chang, Kai-Tai; Zucchi, Paola C; Francoeur, Dennis N; Ledesma, Kimberly R; Tam, Vincent H; Lasco, Todd M

2014-03-01

321

EFECTO DEL USO DE ALCOHOL EN GEL SOBRE LAS INFECCIONES NOSOCOMIALES POR Klebsiella pneumoniae MULTIRRESISTENTE  

Microsoft Academic Search

Effect of alcohol-gel hand hygiene on nosocomial infections due to multi-resistant Klebsiella pneumoniae. Handwashing is considered the most important and effective infection control measure to prevent transmission of nosocomial pathogens. However, compliance with handwashing by health care workers is low. A new modality for hand hygiene is alcohol gel rub, which reduces time required, does not damage the skin and

JOAQUIN BERMEJO; ARNOLDO WERTZ; BLANCA BENCOMO; PATRICIA LESNABERES; RODOLFO NOTARIO

322

Clinical Significance and Mechanism of Gas Formation of Pyogenic Liver Abscess Due to Klebsiella pneumoniae  

PubMed Central

We enrolled 22 patients with gas-forming pyogenic liver abscess in a study to assess the mechanism of gas formation. Klebsiella pneumoniae was cultured from specimens from all patients. Gas and pus samples from abscesses revealed four major components: nitrogen, oxygen, carbon dioxide, and hydrogen; this implicates mixed acid fermentation of glucose as the mechanism of gas formation.

Lee, Hsin-Ling; Lee, Hsin-Chun; Guo, How-Ran; Ko, Wen-Chien; Chen, Kuan-Wen

2004-01-01

323

Immune response and pathophysiological features of Klebsiella pneumoniae liver abscesses in an animal model  

Microsoft Academic Search

Capsular serotypes K1 and K2, the rmpA gene (a regulator of the mucoid phenotype) and aerobactin from Klebsiella pneumoniae have been identified as the major virulence factors for pyogenic liver abscesses with high morbidity, mortality and severe complications. The pathological mechanisms remain unclear. In this study, we compared liver immune responses and pathological changes in response to different serotypes of

Feng-Yee Chang; Jung-Chung Lin; Donald Ming-Tak Ho; Chiung-Tong Chen; Jiun-Han Chen; Kuo-Ming Yeh; Te-Li Chen; Yi-Tsung Lin; L Kristopher Siu

2011-01-01

324

Molecular and Biochemical Characterization of SHV-56, a Novel Inhibitor-Resistant ?-Lactamase from Klebsiella pneumoniae?  

PubMed Central

A clinical strain of Klebsiella pneumoniae was found to possess the chromosomal gene blaSHV-56, encoding a new inhibitor-resistant ?-lactamase with a pI of 7.6. SHV-56 is derived from SHV-11 by the single substitution K234R. This mutation therefore evidences a new critical site for inhibitor resistance among SHV enzymes.

Dubois, Veronique; Poirel, Laurent; Demarthe, Francois; Arpin, Corinne; Coulange, Laure; Minarini, Luciene A. R.; Bezian, Marie-Christine; Nordmann, Patrice; Quentin, Claudine

2008-01-01

325

High-level resistance to cefotaxime and ceftazidime in Klebsiella pneumoniae isolates from Cleveland, Ohio.  

PubMed Central

Two isolates of Klebsiella pneumoniae possessing both TEM-1 and SHV-2 beta-lactamases were isolated from patients at the Cleveland Clinic in 1988. The beta-lactamases were discriminated and identified by using substrate hydrolysis data and an isoelectric focusing procedure in which the gel was overlaid with beta-lactamase inhibitors. Images

Thomson, K S; Sanders, C C; Washington, J A

1991-01-01

326

Investigation of extended-spectrum ?-lactamase in Klebsiellae pneumoniae and Escherichia coli from China  

Microsoft Academic Search

Extended-spectrum ?-lactamases (ESBLs) are an increasing cause of resistance to third-generation cephalosporins in Enterobacteriaceae. However, they have not been well studied in China. We investigated the prevalence, resistance, and probable gene type of ESBLs using MICs testing and polymerase chain reaction in 559 Klebsiellae pneumoniae and 427 Escherichia coli isolates collected from patients in Huashan Hospital from 1 January to

Zizhong Xiong; Demei Zhu; Fu Wang; Yingyuan Zhang; Ryoichi Okamoto; Matsuhisa Inoue

2002-01-01

327

Phenotypic and Molecular Characterization of Multidrug Resistant Klebsiella pneumoniae Isolated from a University Teaching Hospital, China  

PubMed Central

The multidrug-resistant rate of Klebsiella pneumoniae has risen rapidly worldwide. To better understand the multidrug resistance situation and molecular characterization of Klebsiella pneumoniae, a total of 153 Klebsiella pneumoniae isolates were collected, and drug susceptibility test was performed to detect its susceptibility patterns to 13 kinds of antibiotics. Phenotypic tests for carbapenemases ESBLs and AmpC enzyme-producing strains were performed to detect the resistance phenotype of the isolates. Then PCR amplification and sequencing analysis were performed for the drug resistance determinants. The results showed that 63 strains harbored blaCTX-M gene, and 14 strains harbored blaDHA gene. Moreover, there were 5 strains carrying blaKPC gene, among which 4 strains carried blaCTX-M, blaDHA and blaKPC genes, and these 4 strains were also resistant to imipenem. Our data indicated that drug-resistant Klebsiella pneumoniae were highly prevalent in the hospital. Thus it is warranted that surveillance of epidemiology of those resistant isolates should be a cause for concern, and appropriate drugs should be chosen.

Liu, Helu; Lu, Dongyue; Liang, Hong; Dou, Yuhong

2014-01-01

328

The structural repeating-unit of the capsular polysaccharide from Klebsiella serotype K48.  

PubMed

Investigation of the structure of the capsular polysaccharide from Klebsiella K48, using methylation analysis, periodate oxidation, Smith degradation, and 1H- and 13C-n.m.r. spectroscopy, indicated the repeating unit to be the pentasaccharide (formula; see text) PMID:2850106

Joseleau, J P; Marais, M F

1988-08-15

329

Extracellular melibiose and fructose are intermediates in raffinose catabolism during fermentation to ethanol by engineered enteric bacteria.  

PubMed Central

Contrary to general concepts of bacterial saccharide metabolism, melibiose (25 to 32 g/liter) and fructose (5 to 14 g/liter) accumulated as extracellular intermediates during the catabolism of raffinose (O-alpha-D-galactopyranosyl-1, 6-alpha-D-glucopyranosyl-beta-D-fructofuranoside) (90 g/liter) by ethanologenic recombinants of Escherichia coli B, Klebsiella oxytoca M5A1, and Erwinia chrysanthemi EC16. Both hydrolysis products (melibiose and fructose) were subsequently transported and further metabolized by all three organisms. Raffinose catabolism was initiated by beta-fructosidase; melibiose was subsequently hydrolyzed to galactose and glucose by alpha-galactosidase. Glucose and fructose were completely metabolized by all three organisms, but galactose accumulated in the fermentation broth with EC16(pLOI555) and P2. MM2 (a raffinose-positive E. coli mutant) was the most effective biocatalyst for ethanol production (38 g/liter) from raffinose. All organisms rapidly fermented sucrose (90 g/liter) to ethanol (48 g/liter) at more than 90% of the theoretical yield. During sucrose catabolism, both hydrolysis products (glucose and fructose) were metabolized concurrently by EC16(pLOI555) and P2 without sugar leakage. However, fructose accumulated extracellularly (27 to 28 g/liter) at early stages of fermentation with KO11 and MM2. Sequential utilization of glucose and fructose correlated with a diauxie in base utilization (pH maintenance). The mechanism of sugar escape remains unknown but may involve downhill leakage via permease which transports precursor saccharides or novel sugar export proteins. If sugar escape occurs in nature with wild organisms, it could facilitate the development of complex bacterial communities which are based on the sequence of saccharide catabolism and the hierarchy of sugar utilization.

Moniruzzaman, M; Lai, X; York, S W; Ingram, L O

1997-01-01

330

A Multicenter Study of Beta-Lactamase Resistant Escherichia coli and Klebsiella pneumoniae Reveals High Level Chromosome Mediated Extended Spectrum ? Lactamase Resistance in Ogun State, Nigeria  

PubMed Central

As a result of the ever increasing problem of multiresistant bacteria, we instituted a surveillance program with the aim of identifying the basic molecular properties of ESBL in our environment. About 197 isolates of Escherichia coli and Klebsiella pneumoniae were selected and tested for ESBL production and antimicrobial susceptibility. Plasmid profiles were determined and curing ability was tested. ESBL prevalence was 26.4% for all isolates tested, with E. coli having a greater proportion. There was absolute resistance to ampicilin, tetracycline, and co-trimaxole among tested isolates. There was above average susceptibility to the 2nd and 3rd generation cephalosporins. Plasmid profiles of tested isolates ranged from 9?kbp to 26?kbp with average of 14.99 ± 2.3?kbp for E. coli and 20.98 ± 1.8?kbp K. pneumoniae, 9.6% of ESBL positive E. coli plasmids were cured, while 3.9% of K. pneumoniae plasmids were cured after treatment. The present study shows an upsurge in ESBL acquisition by gram negative bacteria and evidence of cocirculation of varying subtypes of ESBL with both plasmid transmissible and chromosome encoded subtypes. This calls for universal surveillance and more effort towards molecular epidemiology of this public health treatment.

Adeyankinnu, Folasoge A.; Motayo, Babatunde O.; Akinduti, Akinniyi; Akinbo, John; Ogiogwa, Joseph I.; Aboderin, Bukola W.; Agunlejika, R. A.

2014-01-01

331

Emergence of carbapenem-non-susceptible extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates at the university hospital of Tübingen, Germany.  

PubMed

The spread of Gram-negative bacteria with plasmid-borne extended-spectrum beta-lactamases (ESBLs) has become a worldwide problem. This study analysed a total of 366 ESBL-producing Enterobacteriaceae strains isolated from non-selected patient specimens at the university hospital of Tübingen in the period January 2003 to December 2007. Although the overall ESBL rate was comparatively low (1.6 %), the percentages of ESBL-producing Enterobacter spp. and Escherichia coli increased from 0.8 and 0.5 %, respectively, in 2003 to 4.6 and 3.8 % in 2007. In particular, the emergence was observed of one carbapenem-resistant ESBL-producing E. coli isolate and five carbapenem-non-susceptible ESBL-positive Klebsiella pneumoniae isolates, in two of which carbapenem resistance development was documented in vivo under a meropenem-containing antibiotic regime. The possible underlying mechanism for this carbapenem resistance in three of the K. pneumoniae isolates was loss of the Klebsiella porin channel protein OmpK36 as shown by PCR analysis. The remaining two K. pneumoniae isolates exhibited increased expression of a tripartite AcrAB-TolC efflux pump as demonstrated by SDS-PAGE and mass spectrometry analysis of bacterial outer-membrane extracts, which, in addition to other unknown mechanisms, may contribute towards increasing the carbapenem MIC values further. Carbapenem-non-susceptible ESBL isolates may pose a new problem in the future due to possible outbreak situations and limited antibiotic treatment options. Therefore, a systematic exploration of intestinal colonization with ESBL isolates should be reconsidered, at least for haemato-oncological departments from where four of the five carbapenem-non-susceptible ESBL isolates originated. PMID:19502377

Gröbner, Sabine; Linke, Dirk; Schütz, Wolfgang; Fladerer, Claudia; Madlung, Johannes; Autenrieth, Ingo B; Witte, Wolfgang; Pfeifer, Yvonne

2009-07-01

332

The rcsA gene of Klebsiella pneumoniae O1:K20 is involved in expression of the serotype-specific K (capsular) antigen.  

PubMed Central

In Klebsiella pneumoniae, the ability to synthesize large amounts of capsular polysaccharide is an important correlate of virulence. We report the cloning of rcsA from K. pneumoniae serotype O1:K20 and demonstrate that rcsA is involved in the expression of the K antigen capsule. We have determined the nucleotide sequence for the rcsA gene from K. pneumoniae K20 and shown it to be identical to the sequence reported previously for rcsA from strain K21 (Allen et al., J. Gen. Microbiol. 133:331-340, 1987). Southern hybridization results indicate that this gene is widely distributed among different Klebsiella K serotypes. When cloned into Escherichia coli K-12, the K. pneumoniae rcsA gene caused a mucoid phenotype, resulting from the activation of colanic acid synthesis. Activation of colanic acid synthesis was not dependent on growth at low temperatures (less than or equal to 30 degrees C). The K. pneumoniae rcsA gene complemented E. coli K-12 rcsA mutations but could not complement defects in rcsB, suggesting that RcsA may be functionally homologous in these bacteria. The cloned rcsA gene also complemented a defect in nonmucoid strain K20 derivatives that normally produced only trace amounts of K20 antigen and were unable to assemble a wild-type capsular structure. Mutants that were K20-deficient were not complemented. The K antigen capsule of K. pneumoniae therefore joins a growing list of polysaccharide-synthetic systems in which "RcsA-like" proteins are involved. Images

McCallum, K L; Whitfield, C

1991-01-01

333

Detection of AmpC beta-lactamases in Escherichia coli, Klebsiella spp., Salmonella spp. and Proteus mirabilis in a regional clinical microbiology laboratory.  

PubMed

There are currently no standardized diagnostic tests available for the reliable detection of AmpC beta-lactamases in Klebsiella spp., Escherichia coli, Proteus mirabilis and Salmonella spp. A study was designed to evaluate a confirmation disk test using cefotetan (CTT) and cefoxitin (FOX) with phenylboronic acid (PBA). It also investigated the most suitable screening concentrations of FOX, ceftriaxone (CRO) and ceftazidime (CAZ) for the detection of AmpC beta-lactamases. A total of 126 control (consisting of 11 laboratory and 115 well-characterized clinical strains) and 29,840 non-repeat clinical isolates were included. FOX with PBA used in a confirmation test and CRO and CAZ as screening agents were found to be unreliable. FOX at >or= 32 mg/L was the best screening agent and CTT with PBA was the best confirmation test. Of the clinical isolates 635 (2%) were found to be resistant to cefoxitin (MIC >or= 32 ug/mL) and 332 (52%) were AmpC positive. E. coli was the most common organism with AmpC beta-lactamases and was mostly present in urines from community patients. It is recommended that laboratories use FOX at 32 mg/L as a screening agent and perform a disk test with CTT and PBA to confirm the presence of an AmpC cephalosporinase in isolates of Klebsiella spp., E. coli, Salmonella spp. and P. mirabilis. This approach is convenient, practical and easy to incorporate into the workflow of a clinical laboratory. False-positive AmpC detection may occur with KPC-producing bacteria when inhibitor-based methods are used. PMID:19456838

Pitout, J D D; Le, P G; Moore, K L; Church, D L; Gregson, D B

2010-02-01

334

Modeling Klebsiella pneumoniae pathogenesis by infection of the wax moth Galleria mellonella.  

PubMed

The implementation of infection models that approximate human disease is essential for understanding pathogenesis at the molecular level and for testing new therapies before they are entered into clinical stages. Insects are increasingly being used as surrogate hosts because they share, with mammals, essential aspects of the innate immune response to infections. We examined whether the larva of the wax moth Galleria mellonella could be used as a host model to conceptually approximate Klebsiella pneumoniae-triggered pneumonia. We report that the G. mellonella model is capable of distinguishing between pathogenic and nonpathogenic Klebsiella strains. Moreover, K. pneumoniae infection of G. mellonella models some of the known features of Klebsiella-induced pneumonia, i.e., cell death associated with bacterial replication, avoidance of phagocytosis by phagocytes, and the attenuation of host defense responses, chiefly the production of antimicrobial factors. Similar to the case for the mouse pneumonia model, activation of innate responses improved G. mellonella survival against subsequent Klebsiella challenge. Virulence factors necessary in the mouse pneumonia model were also implicated in the Galleria model. We found that mutants lacking capsule polysaccharide, lipid A decorations, or the outer membrane proteins OmpA and OmpK36 were attenuated in Galleria. All mutants activated G. mellonella defensive responses. The Galleria model also allowed us to monitor Klebsiella gene expression. The expression levels of cps and the loci implicated in lipid A remodeling peaked during the first hours postinfection, in a PhoPQ- and PmrAB-governed process. Taken together, these results support the utility of G. mellonella as a surrogate host for assessing infections with K. pneumoniae. PMID:23836821

Insua, José Luis; Llobet, Enrique; Moranta, David; Pérez-Gutiérrez, Camino; Tomás, Anna; Garmendia, Junkal; Bengoechea, José A

2013-10-01

335

Penicillinases of Klebsiella pneumoniae and Their Phylogenetic Relationship to Penicillinases Mediated by R Factors  

PubMed Central

On the assumption that the penicillinase determinants on a group of R factors conferring ampicillin resistance have a phylogenetically close relationship to the penicillinase gene of the Klebsiella group, the penicillinases from four strains of K. pneumoniae, GN69, GN1103R?, GN422, and GN118, were purified 230- to 1,000-fold and compared with the known two R-factor-mediated penicillinases. By gel filtration on Sephadex G-75, the molecular weights were estimated to be 17,400, 18,100, 20,000 and 18,300, respectively, which are slightly lower than those of the R-factor penicillinases. The isoelectric points of the Klebsiella penicillinases were not in agreement with those of the R-factor penicillinases. All the enzymes showed a pH optimum between 6.3 to 7.2 and a temperature optimum of 45 C, and those properties, together with behavior towards inhibitors, were about the same as those in the R-factor penicillinases. The substrate specificity and the Michaelis constants of the Klebsiella penicillinases for penicillins and cephaloridine were broadly similar to those of the R-factor penicillinases, however, some variations were found even among the four penicillinases of K. pneumoniae. The reactivities of the four penicillinases of K. pneumoniae with the antiserum against one R-factor penicillinase were tested, and three of the four Klebsiella penicillinases were found to be indistinguishable immunologically from both R-factor penicillinases. The remaining Klebsiella penicillinase, from GN1103R?, showed an immunological partial homology with the R-factor penicillinases. Images

Sawai, Tetsuo; Yamagishi, Saburo; Mitsuhashi, Susumu

1973-01-01

336

Ceftazidime resistance among Klebsiella pneumoniae in south India.  

PubMed

Fifteen strains of K. pneumoniae resistant to ceftazidime were tested for extended spectrum beta lactamase (ESBL) production by double disc diffusion synergy test using ceftazidime and augmentin, and by testing for reduction in minimum inhibitory concentration of ceftazidime in combination with clavulanic acid. All strains were found to produce ESBL. We document the presence of ESBL producing strains in south India. There is a possibility of the spread of this resistance to other bacteria because the resistance could be transferred to recipient Escherichia coli from two strains. PMID:8834813

Abigail, S; Mathai, E; Jesudason, M V; John, T J

1995-08-01

337

Multi-drug resistant gram-negative enteric bacteria isolated from flies at Chengdu Airport, China.  

PubMed

We collected flies from Chengdu Shuangliu International Airport to examine for the presence of bacteria and to determine the sensitivity patterns of those bacteria. A total of 1,228 flies were collected from 6 sites around Chengdu Shuangliu International Airport from April to September 2011. The predominant species was Chrysomya megacephala (n=276, 22.5%). Antimicrobial-resistant gram-negative enteric bacteria (n=48) were isolated from flies using MacConkey agar supplemented with cephalothin (20 microg/ml). These were identified as Escherichia coli (n=37), Klebsiella pneumoniae (n=6), Pseudomonas aeruginosa (n=3) and Aeromonas hydrophila (n=2). All isolated bacteria were tested for resistance to 21 commonly used antimicrobials: amoxicillin (100%), ticarcillin (100%), cephalothin (100%), cefuroxime (100%), ceftazidime 1 (93.8%), piperacillin (93.8%), cefotaxime (89.6%), ticarcillin-clavulanate (81.3%), trimethoprim-sulfamethoxazole (62.5%), ciprofloxacin (54.2%), gentamicin (45.8%), cefepime (39.6%), tobramycin (39.6%), ceftazidime (22.9%), cefoxitin (16.7%), amikacin (16.7%), netilmicin (14.6%), amoxicillin-clavulanate (6.3%) and piperacillin-tazobactam (2.1%). No resistance to meropenem or imipenem was observed. Antibiotic resistance genes among the isolated bacteria were analyzed for by polymerase chain reaction. Thirty of the 48 bacteria with resistance (62.5%) possessed the blaTEM gene. PMID:24450236

Liu, Yang; Yang, Yu; Zhao, Feng; Fan, Xuejun; Zhong, Wei; Qiao, Dairong; Cao, Yi

2013-11-01

338

Screening, characterization and biofilm formation of nickel resistant bacteria isolated from indigenous environment.  

PubMed

Nickel resistant bacteria (ZB, ZC, ZD, ZL, ZK and S1X) were isolated from industrial effluents and corroded iron pieces from indigenous environment of Punjab, Pakistan. These six strains could tolerate nickel at different levels with ZB, ZC, ZD, ZL, ZK, and S1X having 233, 225, 267, 233, 228 and 296 mM minimum inhibitory concentration (MIC) of nickel ions, respectively. These bacteria were sensitive to Cu(+2), Cr(+3), Co(+2), and Al(+3) as they did not grow even in the presence of 1 mM concentration of all these ions in minimal medium, whereas all of them were resistant to Fe3 upto 1.3 mM in minimal medium. The best appropriate temperature for nickel resistant bacteria was 37 degrees C and all of them showed maximum growth at pH 8. These bacteria were characterized morphologically and biochemically. Biofilm forming ability of the bacteria was checked with and without nickel stress and it was found that strains ZK and S1X were able to form a compact biofilm even under nickel stress. The sequencing of 16S rRNA-encoding genes from these nickel resistant bacteria showed that they belonged to four different genera namely, Klebsiella, Pseudomonas, Bacillus and Cronobacter. PMID:24730136

Wadood, Hafiz Z; Sabri, Anjum N

2013-01-01

339

Isolation, characterization and phylogeny of sponge-associated bacteria with antimicrobial activities from Brazil.  

PubMed

Bacteria associated with marine sponges represent a rich source of bioactive metabolites. The aim of this study was to isolate and characterize bacteria with antimicrobial activities from Brazilian sponges. A total of 158 colony-forming units were isolated from nine sponge species. Among these, 12 isolates presented antimicrobial activities against pathogenic bacteria. Based on comparative sequence analysis of their 16S rRNA genes, the sponge-associated bacterial strains could be subdivided into three phylogenetically different clusters. Five strains were affiliated with Firmicutes (genera Bacillus and Virgibacillus), three with alpha-Proteobacteria (Pseudovibrio sp.) and four with gamma-Proteobacteria (genera Pseudomonas and Stenotrophomonas). The sponge-associated bacterial strains Pseudomonas fluorescens H40 and H41 and Pseudomonas aeruginosa H51 exhibited antimicrobial activity against both Gram-negative and Gram-positive bacteria, including strains such as vancomycin-resistant Enterococcus faecium and multiresistant Klebsiella pneumoniae. Bacillus pumilus Pc31 and Pc32, Pseudovibrio ascidiaceicola Pm31 and Ca31 and Pseudovibrio denitrificans Mm37 strains were more effective against Gram-positive bacteria. These findings suggest that the identified strains may contribute to the search for new sources of antimicrobial substances, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria. PMID:20600863

Santos, Olinda C S; Pontes, Paula V M L; Santos, Juliana F M; Muricy, Guilherme; Giambiagi-deMarval, Marcia; Laport, Marinella S

2010-09-01

340

Bacteria turn tiny gears  

ScienceCinema

Swarms of bacteria turn two 380-micron long gears, opening the possibility of building hybrid biological machines at the microscopic scale. Read more at Wired: http://www.wired.com/wiredscience/2009/12/bacterial-micro-machine/#more-15684 or Scientific American: http://www.scientificamerican.com/article.cfm?id=brownian-motion-bacteria

341

Chemical communication among bacteria  

PubMed Central

Cell–cell communication in bacteria is accomplished through the exchange of chemical signal molecules called autoinducers. This process, called quorum sensing, allows bacteria to monitor their environment for the presence of other bacteria and to respond to fluctuations in the number and/or species present by altering particular behaviors. Most quorum-sensing systems are species- or group-specific, which presumably prevents confusion in mixed-species environments. However, some quorum-sensing circuits control behaviors that involve interactions among bacterial species. These quorum-sensing circuits can involve both intra- and interspecies communication mechanisms. Finally, anti-quorumsensing strategies are present in both bacteria and eukaryotes, and these are apparently designed to combat bacteria that rely on cell–cell communication for the successful adaptation to particular niches.

Taga, Michiko E.; Bassler, Bonnie L.

2003-01-01

342

Risk Factors of Nosocomial Infection with Extended-Spectrum Beta-Lactamase-Producing Bacteria in a Neonatal Intensive Care Unit in China  

Microsoft Academic Search

Background:  To study risk factors of neonatal nosocomial infection caused by extended-spectrum beta-lactamase (ESBL)-producing bacteria\\u000a in a neonatal intensive care unit (NICU).\\u000a \\u000a \\u000a \\u000a Patients and Methods:  A retrospective cohort study was conducted in a university hospital NICU in south China. Medical records of neonatal nosocomial\\u000a infection caused by Escherichia coli or Klebsiella pneumoniae were reviewed. Twenty-two neonates infected with ESBL-producing bacteria (case patients)

Y. Huang; S. Zhuang; M. Du

2007-01-01

343

Electron transfer capacity dependence of quinone-mediated Fe(III) reduction and current generation by Klebsiella pneumoniae L17.  

PubMed

Quinone groups in exogenous electron shuttles can accelerate extracellular electron transfer (EET) from bacteria to insoluble terminal electron acceptors, such as Fe(III) oxides and electrodes, which are important in biogeochemical redox processes and microbial electricity generation. However, the relationship between quinone-mediated EET performance and electron-shuttling properties of the quinones remains incompletely characterized. This study investigates the effects of a series of synthetic quinones (SQs) on goethite reduction and current generation by a fermenting bacterium Klebsiella pneumoniae L17. In addition, the voltammetric behavior and electron transfer capacities (ETCs) of SQ, including electron accepting (EAC) and donating (EDC) capacities, is also examined using electrochemical methods. The results showed that SQ can significantly increase both the Fe(III) reduction rates and current outputs of L17. Each tested SQ reversibly accepted and donated electrons as indicated by the cyclic voltammograms. The EAC and EDC results showed that Carmine and Alizarin had low relative capacities of electron transfer, whereas 9,10-anthraquinone-2,6-disulfonic acid (AQDS), 2-hydroxy-1,4-naphthoquinone (2-HNQ), and 5-hydroxy-1,4-naphthoquinone (5-HNQ) showed stronger relative ETC, and 9,10-anthraquinone-2-carboxylic acid (AQC) and 9,10-anthraquinone-2-sulfonic acid (AQS) had high relative ETC. Enhancement of microbial goethite reduction kinetics and current outputs by SQ had a good linear relationship with their ETC, indicating that the effectiveness of quinone-mediated EET may be strongly dependent on the ETC of the quinones. Therefore, the presence of quinone compounds and fermenting microorganisms may increase the diversity of microbial populations that contribute to element transformation in natural environments. Moreover, ETC determination of different SQ would help to evaluate their performance for microbial EET under anoxic conditions. PMID:23461838

Li, Xiaomin; Liu, Liang; Liu, Tongxu; Yuan, Tian; Zhang, Wei; Li, Fangbai; Zhou, Shungui; Li, Yongtao

2013-06-01

344

Assessment of two penicillins plus beta-lactamase inhibitors versus cefotaxime in treatment of murine Klebsiella pneumoniae infections.  

PubMed Central

The in vivo efficacies of piperacillin, piperacillin plus tazobactam, ticarcillin, ticarcillin plus clavulanic acid, piperacillin plus clavulanic acid, and cefotaxime were compared in a mouse model of pneumonia induced by the SHV-1 beta-lactamase-producer Klebsiella pneumoniae. Each antibiotic was injected either once intraperitoneally at 24 h postinfection or at repeated times during 24 h. The efficacies of the drugs and therapeutic protocols were assessed by counting viable bacteria recovered from the lungs of mice sacrificed at selected times. No emergence of beta-lactam-resistant organisms was detected. Ticarcillin at 300 mg/kg was ineffective. Repeated injections of piperacillin at 300 mg/kg, either alone or in combination with tazobactam (8:1), led to a significant decrease in bacterial counts, but this was followed by bacterial regrowth. The pharmacokinetic analysis demonstrated that this short-lasting antibacterial effect was not due to a failure of piperacillin and/or tazobactam to penetrate the lungs. The combinations of ticarcillin at 300 mg/kg plus clavulanic acid (15:1) and piperacillin at 300 mg/kg plus tazobactam (4:1) were proven to be effective in that they decreased the bacterial burden in the lungs from 10(5) to < 10(3) CFU. This dose effect of tazobactam can be explained by its dose-dependent penetration in the lungs. Cefotaxime at 100 mg/kg and the combination of piperacillin (slightly hydrolyzed by SHV-1) at 300 mg/kg plus clavulanic acid (15:1) led to the best efficacy. Both of these treatments induced a decrease in bacterial counts of nearly 4 log10 units. The survival rates correlated with the quantitative measurements of in vivo bacterial killing. These experimental results obtained from the restricted animal model used here may help in the design of further protocols for clinical trials.

Fournier, J L; Ramisse, F; Jacolot, A C; Szatanik, M; Petitjean, O J; Alonso, J M; Scavizzi, M R

1996-01-01

345

Roles of Glutamate Synthase, gltBD, and gltF in Nitrogen Metabolism of Escherichia coli and Klebsiella aerogenes  

PubMed Central

Mutants of Escherichia coli and Klebsiella aerogenes that are deficient in glutamate synthase (glutamate-oxoglutarate amidotransferase [GOGAT]) activity have difficulty growing with nitrogen sources other than ammonia. Two models have been proposed to account for this inability to grow. One model postulated an imbalance between glutamine synthesis and glutamine degradation that led to a repression of the Ntr system and the subsequent failure to activate transcription of genes required for the use of alternative nitrogen sources. The other model postulated that mutations in gltB or gltD (which encode the subunits of GOGAT) were polar on a downstream gene, gltF, which is necessary for proper activation of gene expression by the Ntr system. The data reported here show that the gltF model is incorrect for three reasons: first, a nonpolar gltB and a polar gltD mutation of K. aerogenes both show the same phenotype; second, K. aerogenes and several other enteric bacteria lack a gene homologous to gltF; and third, mutants of E. coli whose gltF gene has been deleted show no defect in nitrogen metabolism. The argument that accumulated glutamine represses the Ntr system in gltB or gltD mutants is also incorrect, because these mutants can derepress the Ntr system normally so long as sufficient glutamate is supplied. Thus, we conclude that gltB or gltD mutants grow slowly on many poor nitrogen sources because they are starved for glutamate. Much of the glutamate formed by catabolism of alternative nitrogen sources is converted to glutamine, which cannot be efficiently converted to glutamate in the absence of GOGAT activity. Finally, GOGAT-deficient E. coli cells growing with glutamine as the sole nitrogen source increase their synthesis of the other glutamate-forming enzyme, glutamate dehydrogenase, severalfold, but this is still insufficient to allow rapid growth under these conditions.

Goss, Thomas J.; Perez-Matos, Ana; Bender, Robert A.

2001-01-01

346

Isolation and identification of bacteria capable of degrading euptox A from Eupatorium adenophorum Spreng.  

PubMed

Eupatorium adenophorum Spreng (E. adenophorum), an invasive plant which has caused widespread poisoning of livestock and crop failures in China. 9-oxo-10, 11-dehydroageraphorone (known as euptox A) is the main toxin causing a series of respiratory and digestive system diseases in animals. The purpose of the research is to isolate and identify the bacteria with the capacity of degrading euptox A, in which way could we lay the foundation in the utilization and prevention for E. adenophorum. Three strains of bacteria with the degradative characteristic are screened from E. adenophorum leaves, soil and goat's rumen respectively by nutrition enrichment. The 16S rDNA sequence of the three isolated strains (XC-07, XC-08, XC-09) were shown to be 97%, 100%, 100% similar to Stenotrophmonas sp., Klebsiella sp. and Pseudomonas sp., respectively, named as Stenotrophomonas sp. XC-07, Klebsiella sp. XC-08 and Pseudomonas sp. XC-09. The degradation rates of 3 strains to euptox A (45 mg/L) in 24 h are 91.2%, 94.3% and 93.2%, respectively, which are determined by HPLC. PMID:24269687

Liao, Fei; Wang, Yunfei; Huang, Yue; Mo, Quan; Tan, Hui; Wei, Yahui; Hu, Yanchun

2014-01-01

347

Inactivation of biofilm bacteria.  

PubMed Central

The current project was developed to examine inactivation of biofilm bacteria and to characterize the interaction of biocides with pipe surfaces. Unattached bacteria were quite susceptible to the variety of disinfectants tested. Viable bacterial counts were reduced 99% by exposure to 0.08 mg of hypochlorous acid (pH 7.0) per liter (1 to 2 degrees C) for 1 min. For monochloramine, 94 mg/liter was required to kill 99% of the bacteria within 1 min. These results were consistent with those found by other investigators. Biofilm bacteria grown on the surfaces of granular activated carbon particles, metal coupons, or glass microscope slides were 150 to more than 3,000 times more resistant to hypochlorous acid (free chlorine, pH 7.0) than were unattached cells. In contrast, resistance of biofilm bacteria to monochloramine disinfection ranged from 2- to 100-fold more than that of unattached cells. The results suggested that, relative to inactivation of unattached bacteria, monochloramine was better able to penetrate and kill biofilm bacteria than free chlorine. For free chlorine, the data indicated that transport of the disinfectant into the biofilm was a major rate-limiting factor. Because of this phenomenon, increasing the level of free chlorine did not increase disinfection efficiency. Experiments where equal weights of disinfectants were used suggested that the greater penetrating power of monochloramine compensated for its limited disinfection activity. These studies showed that monochloramine was as effective as free chlorine for inactivation of biofilm bacteria. The research provides important insights into strategies for control of biofilm bacteria. Images

LeChevallier, M W; Cawthon, C D; Lee, R G

1988-01-01

348

Multidrug resistance in hydrocarbon-tolerant Gram-positive and Gram-negative bacteria.  

PubMed

New Gram-positive and Gram-negative bacteria were isolated from Poeni oily sludge, using enrichment procedures. The six Gram-positive strains belong to Bacillus, Lysinibacillus and Rhodococcus genera. The eight Gram-negative strains belong to Shewanella, Aeromonas, Pseudomonas and Klebsiella genera. Isolated bacterial strains were tolerant to saturated (i.e., n-hexane, n-heptane, n-decane, n-pentadecane, n-hexadecane, cyclohexane), monoaromatic (i.e., benzene, toluene, styrene, xylene isomers, ethylbenzene, propylbenzene) and polyaromatic (i.e., naphthalene, 2-methylnaphthalene, fluorene) hydrocarbons, and also resistant to different antimicrobial agents (i.e., ampicillin, kanamycin, rhodamine 6G, crystal violet, malachite green, sodium dodecyl sulfate). The presence of hydrophilic antibiotics like ampicillin or kanamycin in liquid LB-Mg medium has no effects on Gram-positive and Gram-negative bacteria resistance to toxic compounds. The results indicated that Gram-negative bacteria are less sensitive to toxic compounds than Gram-positive bacteria, except one bacteria belonging to Lysinibacillus genus. There were observed cellular and molecular modifications induced by ampicillin or kanamycin to isolated bacterial strains. Gram-negative bacteria possessed between two and four catabolic genes (alkB, alkM, alkB/alkB1, todC1, xylM, PAH dioxygenase, catechol 2,3-dioxygenase), compared with Gram-positive bacteria (except one bacteria belonging to Bacillus genus) which possessed one catabolic gene (alkB/alkB1). Transporter genes (HAE1, acrAB) were detected only in Gram-negative bacteria. PMID:21478643

Stancu, Mihaela Marilena; Grifoll, Magdalena

2011-01-01

349

Interspecies communication in bacteria  

PubMed Central

Until recently, bacteria were considered to live rather asocial, reclusive lives. New research shows that, in fact, bacteria have elaborate chemical signaling systems that enable them to communicate within and between species. One signal, termed AI-2, appears to be universal and facilitates interspecies communication. Many processes, including virulence factor production, biofilm formation, and motility, are controlled by AI-2. Strategies that interfere with communication in bacteria are being explored in the biotechnology industry with the aim of developing novel antimicrobials. AI-2 is a particularly attractive candidate for such studies because of its widespread use in the microbial kingdom.

Federle, Michael J.; Bassler, Bonnie L.

2003-01-01

350

Multidrug Resistance in Bacteria  

PubMed Central

Large amounts of antibiotics used for human therapy, as well as for farm animals and even for fish in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. Multidrug resistance in bacteria may be generated by one of two mechanisms. First, these bacteria may accumulate multiple genes, each coding for resistance to a single drug, within a single cell. This accumulation occurs typically on resistance (R) plasmids. Second, multidrug resistance may also occur by the increased expression of genes that code for multidrug efflux pumps, extruding a wide range of drugs. This review discusses our current knowledge on the molecular mechanisms involved in both types of resistance.

Nikaido, Hiroshi

2010-01-01

351

Transferable resistance to cefotaxime, cefoxitin, cefamandole and cefuroxime in clinical isolates of Klebsiella pneumoniae and Serratia marcescens  

Microsoft Academic Search

Summary In conjugational crosses, threeKlebsiella pneumoniae strains and oneSerratia marcescens strain have been demonstrated to transfer resistance determinants to newer types of cephalosporins. WhileKlebsiella strains donated cefotaxime, cefamandole and cefuroxime resistance toEscherichia coli K-12 recipients, the genetic analysis of exconjugants after the transfer of plasmids fromSerratia strains toProteus orSalmonella recipients showed that the cefoxitin resistance determinant was also co-transferred. In

H. Knothe; P. Shah; V. Krcmery; M. Antal; S. Mitsuhashi

1983-01-01

352

Complete Genome Sequence of the N2-Fixing Broad Host Range Endophyte Klebsiella pneumoniae 342 and Virulence Predictions Verified in Mice  

PubMed Central

We report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, Klebsiella pneumoniae 342. Although K. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world), while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. Genomic analysis examined K. pneumoniae 342 for the presence of previously identified genes from other bacteria involved in colonization of, or growth in, plants. From this set, approximately one-third were identified in K. pneumoniae 342, suggesting additional factors most likely contribute to its endophytic lifestyle. Comparative genome analyses were used to provide new insights into this question. Results included the identification of metabolic pathways and other features devoted to processing plant-derived cellulosic and aromatic compounds, and a robust complement of transport genes (15.4%), one of the highest percentages in bacterial genomes sequenced. Although virulence and antibiotic resistance genes were predicted, experiments conducted using mouse models showed pathogenicity to be attenuated in this strain. Comparative genomic analyses with the presumed human pathogen K. pneumoniae MGH78578 revealed that MGH78578 apparently cannot fix nitrogen, and the distribution of genes essential to surface attachment, secretion, transport, and regulation and signaling varied between each genome, which may indicate critical divergences between the strains that influence their preferred host ranges and lifestyles (endophytic plant associations for K. pneumoniae 342 and presumably human pathogenesis for MGH78578). Little genome information is available concerning endophytic bacteria. The K. pneumoniae 342 genome will drive new research into this less-understood, but important category of bacterial-plant host relationships, which could ultimately enhance growth and nutrition of important agricultural crops and development of plant-derived products and biofuels.

Fouts, Derrick E.; Tyler, Heather L.; DeBoy, Robert T.; Daugherty, Sean; Ren, Qinghu; Badger, Jonathan H.; Durkin, Anthony S.; Huot, Heather; Shrivastava, Susmita; Kothari, Sagar; Dodson, Robert J.; Mohamoud, Yasmin; Khouri, Hoda; Roesch, Luiz F. W.; Krogfelt, Karen A.; Struve, Carsten; Triplett, Eric W.; Methe, Barbara A.

2008-01-01

353

Bacteria and Foodborne Illness  

MedlinePLUS

... types of bacteria cause foodborne illnesses. Examples include Salmonella , a bacterium found in many foods, including raw and undercooked meat, poultry, dairy products, and seafood. Salmonella may also be present on egg shells and ...

354

Cultivation Media for Bacteria  

NSDL National Science Digital Library

Common bacteriological culture media (tryptic soy agar, chocolate agar, Thayer-Martin agar, MacConkey agar, eosin-methylene blue agar, hektoen agar, mannitol salt agar, and sheep blood agar) are shown uninoculated and inoculated with bacteria.

American Society For Microbiology;

2009-12-08

355

Ecophysiology of Magnetotactic Bacteria  

Microsoft Academic Search

Magnetotactic bacteria are a physiologically diverse group of prokaryotes whose main common features\\u000a are the biomineralization of magnetosomes and magnetotaxis, the passive alignment and active motility along\\u000a geomagnetic field lines. Magnetotactic bacteria exist in their highest numbers at or near the oxic–anoxic\\u000a interfaces (OAI) of chemically stratified aquatic habitats that contain inverse concentration gradients\\u000a of oxidants and reductants. Few species are

Dennis A. Bazylinski; Timothy Williams

356

Iron Storage in Bacteria  

Microsoft Academic Search

Iron is an essential nutrient for nearly all organisms but presents problems of toxicity, poor solubility and low availability. These problems are alleviated through the use of iron-storage proteins. Bacteria possess two types of iron-storage protein, the haemcontaining bacterioferritins and the haem-free ferritins. These proteins are widespread in bacteria, with at least 39 examples known so far in eubacteria and

Simon C. Andrews

1998-01-01

357

Enterotoxigenic Bacteria in Food and Water from an Ethiopian Community  

PubMed Central

Food and water samples from an Ethiopian community were screened for the presence of enterotoxin-producing bacteria. Using the Chinese hamster ovary cell assay, 40 of 213 isolates (18.8%) produced heat-labile (LT) enterotoxin. These LT-producing isolates comprised 33 of 177 (18.6%) strains from 24 of 68 food samples (35.3%) and 7 of 36 (19.4%) isolates of 4 of 17 water samples (23.5%). One LT-producing strain each of Salmonella emek and of Shigella dysenteriae was found. Three pseudomonads, all LT producers, produced heat-stable enterotoxin as gauged by the suckling mouse test. Two strains of LT-enterotoxigenic Escherichia coli O68 were found in water samples. No enterotoxigenic E. coli were isolated from food samples, but 13 of the LT-producing strains were Enterobacter, Klebsiella, Serratia, and Proteus species, and 7 food samples yielded more than one species of enterotoxigenic bacterium. Of the enterotoxigenic isolates from food, 15 were oxidase-positive strains of the genera Aeromonas, Pseudomonas, Achromobacter, Flavobacterium, and Vibrio. LT-enterotoxigenic Enterobacter, Acinetobacter, Klebsiella, Proteus, Providencia, and Serratia species represented 20 of the food and water isolates. Culture supernatant fluids of representative strains of oxidase-positive and oxidase-negative species giving positive reactions in Chinese hamster ovary cell tests induced fluid accumulation in rabbit ileal loops. Eight of the food samples and two of the water samples contained more than one isolate or species of enterotoxigenic bacterium. The stability of the LT production by oxidase-positive bacteria and non-E. coli strains was assessed by the rabbit skin and adrenal cell tests after 9 months and 1 year of storage, respectively, in Trypticase soy broth with glycerol at ?70°C. Only 33% of the oxidase-positive strains were still LT enterotoxigenic. Of the oxidase-negative strains, 50 and 33% were LT producing at 9 months and 1 year, respectively. None of the E. coli isolates, both enterotoxigenic and nonenterotoxigenic, possessed K88, K99, or colonization factor antigen. The survey demonstrates the presence in food and water of enterotoxigenic bacteria of the same species as those isolated from cases of infantile diarrhea in the same community, although a correlation between these sources and infantile diarrhea remains to be established. Images

Jiwa, Sadruddin F. H.; Krovacek, Karel; Wadstrom, Torkel

1981-01-01

358

Aerobic Anoxygenic Phototrophic Bacteria  

PubMed Central

The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynthetically under anaerobic conditions. Aerobic anoxygenic phototrophic bacteria are classified in two marine (Erythrobacter and Roseobacter) and six freshwater (Acidiphilium, Erythromicrobium, Erythromonas, Porphyrobacter, Roseococcus, and Sandaracinobacter) genera, which phylogenetically belong to the ?-1, ?-3, and ?-4 subclasses of the class Proteobacteria. Despite this phylogenetic information, the evolution and ancestry of their photosynthetic properties are unclear. We discuss several current proposals for the evolutionary origin of aerobic phototrophic bacteria. The closest phylogenetic relatives of aerobic phototrophic bacteria include facultatively anaerobic purple nonsulfur phototrophic bacteria. Since these two bacterial groups share many properties, yet have significant differences, we compare and contrast their physiology, with an emphasis on morphology and photosynthetic and other metabolic processes.

Yurkov, Vladimir V.; Beatty, J. Thomas

1998-01-01

359

Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to Brown Tree Frogs (Litoria ewingii)  

PubMed Central

Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 × 107 cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals.

Schadich, Ermin; Cole, Anthony LJ

2010-01-01

360

Clinical Disease Caused by Klebsiella in 2 Unrelated Patients With Interleukin 12 Receptor ?1 Deficiency  

PubMed Central

Patients with interleukin 12 (IL-12)p40 or IL-12 receptor ?1 (IL12R?1) deficiencies are prone to develop infections caused by mycobacteria and salmonella; other infections have only been rarely observed. In this report we describe 2 unrelated patients with complete autosomal recessive IL12R?1 deficiency who suffered from sepsis attributable to Klebsiella pneumoniae. A Mexican boy suffered from disseminated bacilli Calmette-Guérin disease and infections caused by K pneumoniae and Candida albicans and had a fatal outcome. A Turkish girl living in France suffered from disseminated Nocardia nova infection and K pneumoniae sepsis. Therefore, Klebsiella infections should be considered in patients with IL12R?1 deficiency. Conversely, IL12R?1 deficiency should be considered in patients with unexplained klebsiellosis.

Pedraza, Sigifredo; Lezana, Jose Luis; Samarina, Arina; Aldana, Ruth; Herrera, Maria Teresa; Boisson-Dupuis, Stephanie; Bustamante, Jacinta; Pages, Perle; Casanova, Jean-Laurent; Picard, Capucine

2010-01-01

361

Assessment of pathogenic bacteria in treated graywater and irrigated soils.  

PubMed

Reuse of graywater (GW) for irrigation is recognized as a sustainable solution for water conservation. One major impediment for reuse of GW is the possible presence of pathogenic microorganisms. The presence and abundance of six pathogens and indicators were investigated in three GW recirculating vertical flow constructed wetland treatment systems and their respective irrigated yard soils. The treated GW and soils were monitored once every two months for six months using real-time quantitative PCR. As a control, samples from four soils irrigated with fresh water (FW) were similarly analyzed for pathogens and indicators. Comparable types of pathogens and fecal indicator bacteria, including Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Pseudomonas aeruginosa, Enterococcus faecalis, and Shigella spp., were found in the treated GW, their corresponding irrigated soils and the FW-irrigated soils. Moreover, the abundance of these bacteria in the GW- and FW-irrigated soils was of the same order of magnitude, suggesting that the source of the pathogens cannot be established. Our results suggest that GW irrigation has no effect on the diversity and abundance of the tested pathogens and indicators in yard soils. PMID:23666359

Benami, Maya; Gross, Amit; Herzberg, Moshe; Orlofsky, Ezra; Vonshak, Ahuva; Gillor, Osnat

2013-08-01

362

In Vivo Emergence of Tigecycline Resistance in Multidrug-Resistant Klebsiella pneumoniae and Escherichia coli  

PubMed Central

Although resistance to tigecycline has been reported in surveillance studies, very few reports have described the emergence of resistance in vivo. We report two cases of patients with infections due to SHV-12-producing Klebsiella pneumoniae and K. pneumoniae carbapenemase-3 (KPC-3)-producing Escherichia coli, which developed tigecycline resistance in vivo after treatment. The reported limited experience underlines the risk of occurrence of a tigecycline MIC increase under treatment pressure.

Spanu, Teresa; De Angelis, Giulia; Cipriani, Michela; Pedruzzi, Barbara; D'Inzeo, Tiziana; Cataldo, Maria Adriana; Sganga, Gabriele

2012-01-01

363

Ertapenem Resistance among Extended-Spectrum--Lactamase-Producing Klebsiella pneumoniae Isolates  

Microsoft Academic Search

Ertapenem resistance in Klebsiella pneumoniae is rare. We report on an ertapenem-nonsusceptible phenotype among 25 out of 663 (3.77%) extended-spectrum--lactamase (ESBL)-producing K. pneumoniae isolates in a multicenter Israeli study. These isolates originated from six different hospitals and were multiclonal, belonging to 12 different genetic clones. Repeat testing using Etest and agar dilution confirmed ertapenem nonsuscep- tibility in only 15\\/663 (2.3%)

Azita Leavitt; Inna Chmelnitsky; Raul Colodner; Itzhak Ofek; Yehuda Carmeli; Shiri Navon-Venezia

2009-01-01

364

Role of  -Lactamases and Porins in Resistance to Ertapenem and Other  -Lactams in Klebsiella pneumoniae  

Microsoft Academic Search

Ertapenem is a potent carbapenem antibiotic for most clin- ical isolates of Klebsiella pneumoniae, with a typical MIC at which 90% of the isolates tested are inhibited of 0.03 to 0.06 g\\/ml (6, 9), but occasional strains for which the MICs are 16 g\\/ml have been detected (6, 7). In one such strain resistance was dependent on the presence of

George A. Jacoby; Debra M. Mills; Nancy Chow

2004-01-01

365

Pharmacodynamic Profile of Ertapenem against Klebsiella pneumoniae and Escherichia coli in a Murine Thigh Model  

Microsoft Academic Search

The pharmacodynamic profile of ertapenem was evaluated in a neutropenic mouse thigh infection model. Extended-spectrum beta-lactamase (ESBL)-positive and ESBL-negative clinical strains of Escherichia coli and Klebsiella pneumoniae were studied. MICs ranged from 0.0078 to 0.06 g\\/ml with standard inoculum tests. Ertapenem doses were administered once to five times daily to achieve various exposures, reported as the percentage of the dosing

Dana Maglio; Mary Anne Banevicius; Christina Sutherland; Chinedum Babalola; Charles H. Nightingale; David P. Nicolau

2005-01-01

366

Ertapenem resistance among Klebsiella and Enterobacter submitted in the UK to a reference laboratory  

Microsoft Academic Search

The emergence of carbapenem resistance in Enterobacteriaceae represents a major public health concern. We investigated ertapenem-resistant clinical isolates of Klebsiella spp. and Enterobacter spp. referred to the UK's national reference laboratory for antibiotic resistance. Minimum inhibitory concentrations (MICs) were determined and interpreted according to British Society for Antimicrobial Chemotherapy guidelines. Genes for carbapenemases and CTX-M extended-spectrum ?-lactamases (ESBLs) were sought

Neil Woodford; John W. T. Dallow; Robert L. R. Hill; Marie-France I. Palepou; Rachel Pike; M. Elaina Ward; Marina Warner; David M. Livermore

2007-01-01

367

An outbreak of hospital-acquired Klebsiella pneumoniae bacteraemia, including strains producing extended-spectrum ?-lactamase  

Microsoft Academic Search

This study describes the clinical outcome of an outbreak of extended-spectrum ?-lactamase producingKlebsiella pneumoniae (ESBL-KP) bacteraemia. Ninety-two episodes of hospital-acquired K. pneumoniae bacteraemia were studied, 49 ESBL-KP and 43 non-ESBL-KP, from May 1993 to June 1995. Of these, 44 (90%) episodes of ESBL-KP vs. 20 (46%) episodes of non-ESBL-KP occurred in intensive care unit (ICU) patients. The incidence of K.

C. Peña; M. Pujol; C. Ardanuy; A. Ricart; R. Pallarés; J. Liñares; J. Ariza; F. Gudiol

2001-01-01

368

Influence of phosphate on rhamnose-containing exopolysaccharide rheology and production by Klebsiella I-714  

Microsoft Academic Search

Physiological conditions enhancing rhamnose-containing polysaccharide synthesis by Klebsiella I-714 were studied in batch culture (0.3-l and 2-l bioreactors). The four carbon sources tested, sucrose, sorbitol, Neosorb\\u000a and Cerelose, allowed exopolysaccharide production. Larger amounts of polymer were produced when high carbon\\/nitrogen ratios\\u000a and complex nitrogen sources were used. Exopolysaccharide synthesis was greatest at 30?°C, which was a suboptimal growth temperature.\\u000a A

J. Farrés; G. Caminal; J. López-Santín

1997-01-01

369

Liver abscess due to Klebsiella pneumoniae in a healthy 12-year-old boy  

PubMed Central

Pyogenic liver abscess (PLA) is rare in healthy children. We report a case of PLA in an immunocompetent 12-year-old boy. Percutaneous catheter drainage was performed for the abscess. In addition, parenteral antibiotics were administered for 3 weeks. Klebsiella pneumoniae was detected in the culture of blood and drained fluid. Here, we present this case and a brief review of the literature on this subject.

Yoon, Da Hye; Jeon, Yeon Jin; Bae, E Young; Jeong, Dae Chul

2013-01-01

370

Study of an outbreak of cefoxitin-resistant Klebsiella pneumoniae in a general hospital.  

PubMed Central

During a 3-month period, six Klebsiella pneumoniae isolates resistant to cefoxitin and penicillin-inhibitor combinations were derived from patients in the intensive care unit of a hospital in Athens, Greece. Enterobacterial repetitive intergenic consensus PCR and pulsed-field gel electrophoresis provided evidence of the clonal origin of the isolates. Conventional techniques and ribotyping were inadequate in proving that the isolates were related. Resistance was due to a plasmidic class C beta-lactamase.

Gazouli, M; Kaufmann, M E; Tzelepi, E; Dimopoulou, H; Paniara, O; Tzouvelekis, L S

1997-01-01

371

Activation of Klebsiella pneumoniae and Rhizobium meliloti Nitrogenase Promoters by gln (ntr) Regulatory Proteins  

Microsoft Academic Search

We have studied the expression, in different Escherichia coli gln (ntr) mutants, of fusions (constructed in vitro) of the nifHDK (nitrogenase) promoters from Klebsiella pneumoniae and Rhizobium meliloti to E. coli lacZ. Derepression of the K. pneumoniae nifH::lacZ fusion requires the glnF (ntrA) gene product in addition to the K. pneumoniae nifA gene product, indicating that regulation of the K.

Venkatesan Sundaresan; David W. Ow; Frederick M. Ausubel

1983-01-01

372

An outbreak of multiply-resistant Klebsiella pneumoniae in the Grampian region of Scotland  

Microsoft Academic Search

A predominantly hospital-based outbreak of multiply-resistant Klebsiella pneumoniae capsular type K2 (MRK) expressing expanded spectrum ?-lactamase (ESBL) activity and fully sensitive only to the carbapenems and amikacin is described. The organism was isolated from 283 patients between March 1992 and September 1995. The outbreak started in the intensive care unit (ICU) of a major acute hospital and spread through surgical

R. P. Hobson; F. M. MacKenzie; I. M. Gould

1996-01-01

373

The influence of lignin degradation products on xylose fermentation by Klebsiella pneumoniae  

Microsoft Academic Search

The inhibitory effects of seven closely related lignin degradation products on xylose fermentation by Klebsiella pneumoniae were studied. Compounds were added in varying concentrations. Less heavily substituted phenolics (at concentrations of, 0.1–0.4 g\\/l) were more inhibitory to growth and solvent production than vanillyl or syringyl derivatives. All of the cultures recovered from this inhibition after a prolonged incubation period. When

Nora K. Nishikawa; Roger Sutcliffe; John N. Saddler

1988-01-01

374

Sources of diversity of carbapenem resistance levels in Klebsiella pneumoniae carrying blaVIM-1  

Microsoft Academic Search

Objectives: To elucidate the mechanisms responsible for the diversity of b-lactam resistance phenotypes among isolates of a VIM-1-producing Klebsiella pneumoniae (VPKP) strain that is endemic in Greek hospitals. Methods: Five VPKP clinical isolates were studied. MICs of b-lactams were determined by agar dilution. PFGE of XbaI-digested genomic DNA was used for typing. Profiles of outer membrane proteins (OMPs) were determined

A. Loli; L. S. Tzouvelekis; E. Tzelepi; A. Carattoli; A. C. Vatopoulos; P. T. Tassios; V. Miriagou

2006-01-01

375

Membrane topology of the Na +\\/citrate transporter CitS of Klebsiella pneumoniae by insertion mutagenesis  

Microsoft Academic Search

The sodium ion dependent citrate transporter of Klebsiella pneumoniae (CitS) is a member of the bacterial 2-hydroxycarboxylate transporter family. Membrane topology models of the protein, largely based on reporter molecule fusions to C-terminally truncated CitS molecules, indicate that the protein traverses the membrane 11 times with the NH2-terminus in the cytoplasm and the COOH-terminus in the periplasm. Furthermore, the structure

Marleen van Geest; Juke S. Lolkema

2000-01-01

376

Differences in the BAL proteome after Klebsiella pneumoniae infection in wild type and SPA\\/- mice  

Microsoft Academic Search

BACKGROUND: Surfactant protein-A (SP-A) has been shown to play a variety of roles related to lung host defense function. Mice lacking SP-A are more susceptible to infection than wild type C57BL\\/6 mice. We studied bronchoalveolar lavage (BAL) protein expression in wild type and SP-A-\\/- mice infected with Klebsiella pneumoniae by 2D-DIGE. METHODS: Mice were infected intratracheally with K. pneumoniae and

Mehboob Ali; Todd M Umstead; Rizwanul Haque; Anatoly N Mikerov; Willard M Freeman; Joanna Floros; David S Phelps

2010-01-01

377

Induction of metachromasy in cationic dye by bacterial cell surface polysaccharide from Klebsiella K10  

NASA Astrophysics Data System (ADS)

Interaction of acidic capsular polysaccharide isolated from Klebsiella serotype K10 with cationic dye pinacyanol chloride has been investigated by spectral measurements, and thermodynamic parameters of the interaction evaluated. The polysaccharide induces metachromasy in the dye, causing a blue-shift from 600 to 490 nm. The spectral properties exhibit chromotropic character of the polymer, and the metachromatic compound is formed with the polyanion/dye-cation stoichiometry of 1:1.

Chakrabarti, Asok; Nath, Ranendu K.; Chakraborty, Ajit K.

1989-01-01

378

Structural investigation of the capsular polysaccharide of Klebsiella serotype K35.  

PubMed

The structure of the capsular polysaccharide (K antigen) of Klebsiella K35 has been established as having the pentasaccharide repeating unit shown ("four plus one" type). The structural investigation utilized the techniques of methylation, beta-elimination, Smith degradation, and partial hydrolysis. N.m.r. spectroscopy (1H and 13C) was used extensively to establish the configurations of the anomeric linkages and to delineate the sequence of the sugars in the structure of the polysaccharide. (Formula: see text). PMID:4092215

Dutton, G G; Lim, A V

1985-12-15

379

The molecular structure of the capsular polysaccharide from Klebsiella type 27.  

PubMed

The capsular polysaccharide of Klebsiella serotype K27 had been investigated by techniques involving methylation analysis, autohydrolysis, and graded hydrolysis with acid. The anomeric configurations of the sugar constituents were determined, where possible, on the basis of p.m.r. spectroscopy and optical rotation data. The results of these studies are consistent with a primary structure in which the repeating-unit is the doubly branched hexasaccharide. PMID:7371042

Churms, S C; Merrifield, E H; Stephen, A M

1980-05-01

380

Studies of the primary structure of the capsular polysaccharide from Klebsiella serotype K15.  

PubMed

The capsular polysaccharide of Klebsiella serotype K15 has been investigated mainly by methylation analysis, characterisation of the oligosaccharides obtained by partial acid hydrolysis, periodate oxidation, enzymic degradation, and 1H- and 13C-n.m.r. spectroscopy, and shown to have the hexasaccharide repeating-unit 1. The glycan does not contain any pyruvic acetal or O-acetyl substituents. (formula; see text) PMID:3568000

Nath, K; Chakraborty, A K

1987-03-15

381

Ceftazidime-resistant Klebsiella pneumoniae bloodstream infection in children with febrile neutropenia  

Microsoft Academic Search

Objectives: To evaluate prevalence of ceftazidime-resistant Klebsiella pneumoniae (CRKP) in the pediatric oncology unit of University Hospital, Kuala, Lumpur, and to identify differences between febrile neutropenic pediatric patients with CRKP and ceftazidime-sensitive K. pneumoniae (CSKP) bacteremia.Materials and Methods: Febrile neutropenic patients treated between January 1996 and December 1997 at the pediatric oncology unit of University Hospital, Kuala Lumpur, were prospectively

Hany Ariffin; Parasakthi Navaratnam; Mahfuzah Mohamed; Anusha Arasu; Wan Ariffin Abdullah; Chan Lee Lee; Lin Hai Peng

2000-01-01

382

wzi Gene Sequencing, a Rapid Method for Determination of Capsular Type for Klebsiella Strains  

PubMed Central

Pathogens of the genus Klebsiella have been classified into distinct capsular (K) types for nearly a century. K typing of Klebsiella species still has important applications in epidemiology and clinical microbiology, but the serological method has strong practical limitations. Our objective was to evaluate the sequencing of wzi, a gene conserved in all capsular types of Klebsiella pneumoniae that codes for an outer membrane protein involved in capsule attachment to the cell surface, as a simple and rapid method for the prediction of K type. The sequencing of a 447-nucleotide region of wzi distinguished the K-type reference strains with only nine exceptions. A reference wzi sequence database was created by the inclusion of multiple strains representing K types associated with high virulence and multidrug resistance. A collection of 119 prospective clinical isolates of K. pneumoniae were then analyzed in parallel by wzi sequencing and classical K typing. Whereas K typing achieved typeability for 81% and discrimination for 94.4% of the isolates, these figures were 98.1% and 98.3%, respectively, for wzi sequencing. The prediction of K type once the wzi allele was known was 94%. wzi sequencing is a rapid and simple method for the determination of the K types of most K. pneumoniae clinical isolates.

Passet, Virginie; Haugaard, Anita Bjork; Babosan, Anamaria; Kassis-Chikhani, Najiby; Struve, Carsten; Decre, Dominique

2013-01-01

383

Endogenous Klebsiella Endophthalmitis Associated with Liver Abscess: First Case Report from Iran  

PubMed Central

Purpose To report the first case of endogenous Klebsiella endophthalmitis associated with liver abscess in Iran. Case Report A 79-year-old man was referred to our hospital due to severe pain and visual loss in the left eye. On physical examination, conjunctival hyperemia, corneal edema, hypopyon and severe vitreous cellular reaction were identified in the left eye; however, yellowish conjunctival discoloration was more apparent in the right eye. Abdominal CT scan showed a right liver lobe abscess that was confirmed by sonographically guided percutaneous liver mass biopsy. Blood, vitreous and liver mass aspirate cultures revealed Klebsiella pneumoniae growth. The patient was thus diagnosed with endogenous Klebsiella endophthalmitis secondary to bacteremia associated with liver abscess. Conclusion This report suggests that, rather than being confined to Taiwan, endogenous endophthalmitis secondary to a liver abscess due to K. pneumoniae may be a global problem. Therefore, physicians should be aware of the possibility of endophthalmitis whenever a patient with K. pneumoniae liver abscess complains of ocular symptoms.

Dehghani, A.R.; Masjedi, A.; Fazel, F.; Ghanbari, H.; Akhlaghi, M.; Karbasi, N.

2011-01-01

384

Development of a new trend conjugate vaccine for the prevention of Klebsiella pneumoniae  

PubMed Central

Klebsiella pneumoniae is a major cause of nosocomial pneumonia, septicemia and urinary tract infections, especially in newborns, blood cancer patients, and other immunocompromised candidates. The control of K. pneumoniae is a complicated issue due to its tight pathogenesis. Immuno-prophylactic preparations, especially those directed toward the bacterium O-antigen, showed to be the most successful way to prevent the infection incidence. However, all previously proposed preparations were either of limited spectrum or non-maternal, and hence not targeting the main Klebsiella patients. Moreover, all preparations were directed only to prevent the respiratory diseases due to that pathogen. This article addresses the development of a method originally used to purify the non-capsular bacterial-endotoxins, as a new and easy method for vaccine production against K. pneumoniae. The application of this method was preceded by a biotechnological control of capsular polysaccharide production in K. pneumoniae. The new produced natural conjugate between the bacterial O-antigen and its outer membrane proteins was evaluated by physicochemical and immunological methods to investigate its purity, integrity, safety and immunogenicity. It showed to be pure, stable, safe for use, and able to elicit a protective immunoglobulin titer against different Klebsiella infections. This immune-response proved to be transferable to the offspring of the vaccinated experimental rabbits via placenta.

Ahmad, Tarek A.; Haroun, Medhat; Hussein, Ahmad A.; El Ashry, El Sayed H.; El-Sayed, Laila H.

2012-01-01

385

Substrate specificity of the glycanase activity associated with particles of Klebsiella bacteriophage no. 6.  

PubMed

A glycanase activity associated with the particles of Klebsiella bacteriophage No. 6 catalyses cleavage of O-beta-D-glycopyranosyl-(1 leads to 3)-4,6-O-(1-carboxyethylidene)-beta-D-mannopyranose linkages in Klebsiella serotype-6 capsular polysaccharide. Of 74 heterologous Klebsiella polysaccharides and two derivatives of the type-6 glycan, only the type-1 and type-57 polymers were additionally degraded by the phage-6 enzyme. The repeating units in the three substrates have a 1ax leads to 3eq, 1eq leads to eq-linked chain D-gluco- or D-galacto-pyranosyl residue in common (which constitutes the reducing end after glycanase action), and a carboxyl group on the next hexopyranosyl residue. Of the 72 polysaccharides not affected by the viral enzyme, at least the type-11 and type-21 glycans also contain the same homology of primary structure. This indicates that the conformation at the glycanase recognition-site also constitutes an important feature of the substrates. PMID:7214378

Elsässer-Beile, U; Stirm, S

1981-02-01

386

Quantifying the clinical virulence of Klebsiella pneumoniae producing carbapenemase Klebsiella pneumoniae with a Galleria mellonella model and a pilot study to translate to patient outcomes  

PubMed Central

Background Previous studies may have overestimated morbidity and mortality due to Klebsiella pneumoniae producing carbapenemase (KPC) Klebsiella pneumoniae infections because of difficulties in modeling patient comorbidities. This pilot study sought to evaluate KPC virulence by combining clinical and Galleria mellonella models in patients with K. pneumoniae blood stream infections (BSIs). Methods G. mellonella were inoculated using KPC(+) and KPC(?) isolates from these patients. Extent and rapidity of insect mortality was analyzed. Patients were stratified by KPC BSI status. Clinical outcomes of mortality and length of stay post-infection for survivors (LOS) were analyzed. Median virulence scores calculated from the insect studies were imputed in the clinical model. Results The in-vivo model revealed greater mortality in KPC(?) isolates (p?

2014-01-01

387

Structural basis of a physical blockage mechanism for the interaction of response regulator PmrA with connector protein PmrD from Klebsiella pneumoniae.  

PubMed

In bacteria, the two-component system is the most prevalent for sensing and transducing environmental signals into the cell. The PmrA-PmrB two-component system, responsible for sensing external stimuli of high Fe(3+) and mild acidic conditions, can control the genes involved in lipopolysaccharide modification and polymyxin resistance in pathogens. In Klebsiella pneumoniae, the small basic connector protein PmrD protects phospho-PmrA and prolongs the expression of PmrA-activated genes. We previously determined the phospho-PmrA recognition mode of PmrD. However, how PmrA interacts with PmrD and prevents its dephosphorylation remains unknown. To address this question, we solved the x-ray crystal structure of the N-terminal receiver domain of BeF3(-)-activated PmrA (PmrA(N)) at 1.70 ?. With this structure, we applied the data-driven docking method based on NMR chemical shift perturbation to generate the complex model of PmrD-PmrA(N), which was further validated by site-directed spin labeling experiments. In the complex model, PmrD may act as a blockade to prevent phosphatase from contacting with the phosphorylation site on PmrA. PMID:23861396

Luo, Shih-Chi; Lou, Yuan-Chao; Rajasekaran, Mahalingam; Chang, Yi-Wei; Hsiao, Chwan-Deng; Chen, Chinpan

2013-08-30

388

Phytochemistry and Preliminary Assessment of the Antibacterial Activity of Chloroform Extract of Amburana cearensis (Allem?o) A.C. Sm. against Klebsiella pneumoniae Carbapenemase-Producing Strains  

PubMed Central

The chloroform extract of the stem bark of Amburana cearensis was chemically characterized and tested for antibacterial activity.The extract was analyzed by gas chromatography and mass spectrometry. The main compounds identified were 4-methoxy-3-methylphenol (76.7%), triciclene (3.9%), ?-pinene (1.0%), ?-pinene (2.2%), and 4-hydroxybenzoic acid (3.1%). Preliminary antibacterial tests were carried out against species of distinct morphophysiological characteristics: Escherichia coli, Salmonella enterica Serotype Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus. The minimum inhibitory concentration (MIC) was determinate in 96-well microplates for the chloroform extract and an analogue of themain compound identified, which was purchased commercially.We have shown that plant's extract was only inhibitory (but not bactericidal) at the maximum concentration of 6900??g/mL against Pseudomonas aeruginosa and Bacillus cereus. Conversely, the analogue 2-methoxy-4-methylphenol produced MICs ranging from215 to 431??g/mL against all bacterial species.New antibacterial assays conducted with such chemical compound against Klebsiella pneumoniae carbapenemase-producing strains have shown similarMICresults and minimumbactericidal concentration (MBC) of 431??g/mL.We conclude that A. cearensis is a good source of methoxy-methylphenol compounds,which could be screened for antibacterial activity againstmultiresistant bacteria fromdifferent species

Sa, Mirivaldo Barros; Ralph, Maria Taciana; Nascimento, Danielle Cristina Oliveira; Ramos, Clecio Souza; Barbosa, Isvania Maria Serafin; Sa, Fabricio Bezerra; Lima-Filho, J. V.

2014-01-01

389

Oral DAV131, a Charcoal-Based Adsorbent, Inhibits Intestinal Colonization by ?-Lactam-Resistant Klebsiella pneumoniae in Cefotaxime-Treated Mice  

PubMed Central

Antibiotics excreted into the intestinal tract, such as broad-spectrum cephalosporins, disrupt the indigenous microflora, affect colonization resistance (CR), and promote intestinal colonization by resistant bacteria. We tested whether oral DAV131, a charcoal-based adsorbent, would prevent colonization by a cefotaxime (CTX)-resistant Klebsiella pneumoniae strain (PUG-2) in CTX-treated mice. Mice received CTX, saline, CTX and DAV131, or saline and DAV131 for 3 days before oral challenge with 106 CFU of PUG-2. The fecal CTX concentrations and counts of PUG-2 were assayed. Fecal CTX disappeared when DAV131 was given concomitantly with CTX (P < 0.05), and the area under the curve of PUG-2 fecal density was significantly reduced (P < 0.01). In conclusion, reducing intestinal antibiotic exposure with DAV131 may reduce colonization by resistant strains during treatment compared to treatment with CTX only. This might open new possibilities for decreasing the impact of antibiotics on the intestinal microbiota during treatments.

Massias, Laurent; Nguyen, Thu Thuy; Sayah-Jeanne, Sakina; Ducrot, Nicolas; Chachaty, Elisabeth; de Gunzburg, Jean; Andremont, Antoine

2013-01-01

390

Paneth cell ablation in the presence of Klebsiella pneumoniae induces necrotizing enterocolitis (NEC)-like injury in the small intestine of immature mice.  

PubMed

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants. During NEC pathogenesis, bacteria are able to penetrate innate immune defenses and invade the intestinal epithelial layer, causing subsequent inflammation and tissue necrosis. Normally, Paneth cells appear in the intestinal crypts during the first trimester of human pregnancy. Paneth cells constitute a major component of the innate immune system by producing multiple antimicrobial peptides and proinflammatory mediators. To better understand the possible role of Paneth cell disruption in NEC, we quantified the number of Paneth cells present in infants with NEC and found that they were significantly decreased compared with age-matched controls. We were able to model this loss in the intestine of postnatal day (P)14-P16 (immature) mice by treating them with the zinc chelator dithizone. Intestines from dithizone-treated animals retained approximately half the number of Paneth cells compared with controls. Furthermore, by combining dithizone treatment with exposure to Klebsiella pneumoniae, we were able to induce intestinal injury and inflammatory induction that resembles human NEC. Additionally, this novel Paneth cell ablation model produces NEC-like pathology that is consistent with other currently used animal models, but this technique is simpler to use, can be used in older animals that have been dam fed, and represents a novel line of investigation to study NEC pathogenesis and treatment. PMID:22328592

Zhang, Chunxian; Sherman, Michael P; Prince, Lawrence S; Bader, David; Weitkamp, Jörn-Hendrik; Slaughter, James C; McElroy, Steven J

2012-07-01

391

Type 3 Fimbrial Shaft (MrkA) of Klebsiella pneumoniae, but Not the Fimbrial Adhesin (MrkD), Facilitates Biofilm Formation  

PubMed Central

Isolates of Klebsiella pneumoniae are responsible for opportunistic infections, particularly of the urinary tract and respiratory tract, in humans. These bacteria express type 3 fimbriae that have been implicated in binding to eucaryotic cells and matrix proteins. The type 3 fimbriae mediate binding to target tissue using the MrkD adhesin that is associated with the fimbrial shaft comprised of the MrkA protein. The formation of biofilms in vitro by strains of K. pneumoniae was shown to be affected by the production of fimbriae on the bacterial surface. However, a functional MrkD adhesin was not necessary for efficient biofilm formation. Nonfimbriate strains were impaired in their ability to form biofilms. Using isogenic fimbriate and nonfimbriate strains of K. pneumoniae expressing green fluorescent protein it was possible to demonstrate that the presence of type 3 fimbriae facilitated the formation of dense biofilms in a continuous-flowthrough chamber. Transformation of nonfimbriate mutants with a plasmid possessing an intact mrk gene cluster restored the fimbrial phenotype and the rapid ability to form biofilms.

Langstraat, Jennifer; Bohse, Megan; Clegg, Steven

2001-01-01

392

Prediction of major antibiotic resistance in Escherichia coli and Klebsiella pneumoniae in Singapore, USA and China using a limited set of gene targets.  

PubMed

Antibiotic resistance in Gram-negative bacteria, especially Enterobacteriaceae, can be conferred by a large number of different acquired resistance genes, although it appears that relatively few dominate. A previous survey of Escherichia coli and Klebsiella pneumoniae isolates from Sydney, Australia, revealed that a limited set of genes could reliably predict resistance to third-generation cephalosporins (3GCs) and aminoglycosides. Here we tested E. coli and K. pneumoniae isolates with a cefotaxime, ceftriaxone and/or ceftazidime minimum inhibitory concentration of ?2?g/mL from China and Singapore, with significantly higher resistance rates than Australia, as well as the USA. Few targets were needed to predict non-susceptibility to 3GCs (95/95; 100%) and gentamicin (47/51; 92%). The gene types detected here are consistent with previous surveys in similar countries with similar resistance rates, where the majority of 3GC resistance can be explained by blaCTX-M genes. This study identified a limited set of genes capable of predicting resistance to 3GC and aminoglycoside antibiotics and implies a restriction in the global resistance gene pool that can be exploited for diagnostic purposes. PMID:24721234

Ginn, Andrew N; Wiklendt, Agnieszka M; Zong, Zhiyong; Lin, Raymond T P; Teo, Jeanette W P; Tambyah, Paul A; Peterson, Lance R; Kaul, Karen; Partridge, Sally R; Iredell, Jonathan R

2014-06-01

393

Characterization of the gene cluster involved in allantoate catabolism and its transcriptional regulation by the RpiR-type repressor HpxU in Klebsiella pneumoniae.  

PubMed

Bacteria, fungi, and plants have metabolic pathways for the utilization of nitrogen present in purine bases. In Klebsiella pneumoniae, the genes responsible for the assimilation of purine ring nitrogen are distributed in three separated clusters. We characterized the gene cluster involved in the metabolism of allantoate (genes KPN_01761 to KPN_01771). The functional assignments of HpxK, as an allantoate amidohydrolase, and of HpxU, as a regulator involved in the control of allantoate metabolism, were assessed experimentally. Gene hpxU encodes a repressor of the RpiR family that mediates the regulation of this system by allantoate. In this study, the binding of HpxU to the hpxF promoter and to the hpxU-hpxW intergenic region containing the divergent promoter for these genes was evidenced by electrophoretic mobility shift assays. Allantoate released the HpxU repressor from its target operators whereas other purine intermediate metabolites, such as allantoin and oxamate, failed to induce complex dissociation. Sequence alignment of the four HpxU identified operators identified TGAA-N8-TTCA as the consensus motif recognized by the HpxU repressor. PMID:24568032

Guzmán, Karla; Campos, Evangelina; Aguilera, Laura; Toloza, Lorena; Giménez, Rosa; Aguilar, Juan; Baldoma, Laura; Badia, Josefa

2013-09-01

394

Bacteria-surface interactions  

PubMed Central

The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

Tuson, Hannah H.; Weibel, Douglas B.

2013-01-01

395

Communication among Oral Bacteria  

PubMed Central

Human oral bacteria interact with their environment by attaching to surfaces and establishing mixed-species communities. As each bacterial cell attaches, it forms a new surface to which other cells can adhere. Adherence and community development are spatiotemporal; such order requires communication. The discovery of soluble signals, such as autoinducer-2, that may be exchanged within multispecies communities to convey information between organisms has emerged as a new research direction. Direct-contact signals, such as adhesins and receptors, that elicit changes in gene expression after cell-cell contact and biofilm growth are also an active research area. Considering that the majority of oral bacteria are organized in dense three-dimensional biofilms on teeth, confocal microscopy and fluorescently labeled probes provide valuable approaches for investigating the architecture of these organized communities in situ. Oral biofilms are readily accessible to microbiologists and are excellent model systems for studies of microbial communication. One attractive model system is a saliva-coated flowcell with oral bacterial biofilms growing on saliva as the sole nutrient source; an intergeneric mutualism is discussed. Several oral bacterial species are amenable to genetic manipulation for molecular characterization of communication both among bacteria and between bacteria and the host. A successful search for genes critical for mixed-species community organization will be accomplished only when it is conducted with mixed-species communities.

Kolenbrander, Paul E.; Andersen, Roxanna N.; Blehert, David S.; Egland, Paul G.; Foster, Jamie S.; Palmer, Robert J.

2002-01-01

396

PATHOGENICITY OF BIOFILM BACTERIA  

EPA Science Inventory

There is a paucity of information concerning any link between the microorganisms commonly found in biofilms of drinking water systems and their impacts on human health. For bacteria, culture-based techniques detect only a limited number of the total microorganisms associated wit...

397

Antibiotic-Resistant Bacteria.  

ERIC Educational Resources Information Center

A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

Longenecker, Nevin E.; Oppenheimer, Dan

1982-01-01

398

pIMP-PH114 carrying bla IMP-4 in a Klebsiella pneumoniae strain is closely related to other multidrug-resistant IncA/C2 plasmids.  

PubMed

The IncA/C plasmids are broad host-range vehicles which have been associated with wide dissemination of CMY-2 among Enterobacteriaceae of human and animal origins. Acquired metallo-?-lactamases (MBLs) such as the IMP-type enzymes are increasingly reported in multidrug-resistant Gram-negative bacteria worldwide, particularly in Enterobacteriaceae. We described the complete sequence of the first IMP-4-encoding IncA/C2 plasmid, pIMP-PH114 (151,885 bp), from a sequence type 1 Klebsiella pneumoniae strain that was recovered from a patient who was hospitalized in the Philippines. pIMP-PH114 consists of a backbone from the IncA/C2 plasmids, with the insertion of a novel Tn21-like class 1 integron composite structure (containing the cassette array bla IMP-4-qacG-aacA4-catB3, followed by a class C ?-lactamase bla DHA-1 and the mercury resistance operon, merRTPCADE) and a sul2-floR encoding region. Phylogenetic analysis of the IncA/C repA sequences showed that pIMP-PH114 formed a subgroup with other IncA/C plasmids involved in the international spread of CMY-2, TEM-24 and NDM-1. Identical bla IMP-4 arrays have been described among different Enterobacteriaceae and Acinetobacter spp. in China, Singapore and Australia but the genetic context is different. The broad host range of IncA/C plasmids may have facilitated dissemination of the bla IMP-4 arrays among different diverse groups of bacteria. PMID:24121549

Ho, Pak-Leung; Lo, Wai-U; Chan, Jane; Cheung, Yuk-Yam; Chow, Kin-Hung; Yam, Wing-Cheong; Lin, Chi-Ho; Que, Tak-Lun

2014-02-01

399

Genome Sequences of Two Klebsiella pneumoniae Isolates from Different Geographical Regions, Argentina (Strain JHCK1) and the United States (Strain VA360)  

PubMed Central

We report the sequences of two Klebsiella pneumoniae clinical isolates, strains JHCK1 and VA360, from a newborn with meningitis in Buenos Aires, Argentina, and from a tertiary care medical center in Cleveland, OH, respectively. Both isolates contain one chromosome and at least five plasmids; isolate VA360 contains the Klebsiella pneumoniae carbapenemase (KPC) gene.

Xie, Gary; Ramirez, Maria S.; Marshall, Steven H.; Hujer, Kristine M.; Lo, Chien-Chi; Johnson, Shannon; Li, Po-E; Davenport, Karen; Endimiani, Andrea; Bonomo, Robert A.; Chain, Patrick S. G.

2013-01-01

400

Outbreak of carbapenemase-producing Klebsiella pneumoniae neurosurgical site infections associated with a contaminated shaving razor used for preoperative scalp shaving.  

PubMed

Between July 5 and 21, 2011, an outbreak of neurosurgical site infections with carbapenemase-producing Klebsiella pneumonia occurred in a tertiary care hospital. The outbreak affected 7 patients. The subsequent investigation revealed that a barber's contaminated shaving razor may have caused the carbapenemase-producing Klebsiella pneumonia outbreak. Standardized skin preparation performed by registered nurses using sterilized instruments should be emphasized. PMID:24792718

Dai, Yuanyuan; Zhang, Chengfang; Ma, Xiaoling; Chang, Wenjiao; Hu, Shoukui; Jia, Hengmin; Huang, Jiaxiang; Lu, Huaiwei; Li, Hua; Zhou, Shusheng; Qiu, Guangkuo; Liu, Jiaqin

2014-07-01

401

Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005-2010  

PubMed Central

Background Hospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections. Findings Two thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%), but exhibited lower rates for levofloxacin (18.2% vs 56%). Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems. Conclusions E. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%). This finding represents a disturbing development in a common nosocomial and community pathogen.

2012-01-01

402

Isolation and characterization of plant growth promoting endophytic diazotrophic bacteria from Korean rice cultivars.  

PubMed

We have isolated 576 endophytic bacteria from the leaves, stems, and roots of 10 rice cultivars and identified 12 of them as diazotrophic bacteria using a specific primer set of nif gene. Through 16S rDNA sequence analysis, nifH genes were confirmed in the two species of Penibacillus, three species of Microbacterium, three Bacillus species, and four species of Klebsiella. Rice seeds treated with these plant growth-promoting bacteria (PGPB) showed improved plant growth, increased height and dry weight and antagonistic effects against fungal pathogens. In addition, auxin and siderophore producing ability, and phosphate solubilizing activity were studied for the possible mechanisms of plant growth promotion. Among 12 isolates tested, 10 strains have shown higher auxin producing activity, 6 isolates were confirmed as strains with high siderophore producing activity while 4 isolates turned out to have high phosphate-solubilizing activity. These results strongly suggest that the endophytic diazotrophic bacteria characterized in this study could be successfully used to promote plant growth and inducing fungal resistance in plants. PMID:23871145

Ji, Sang Hye; Gururani, Mayank Anand; Chun, Se-Chul

2014-01-20

403

Introduction of Bacteria In ovo.  

National Technical Information Service (NTIS)

A method and apparatus for introducing probiotic bacteria into the digestive tract of a bird in order to exclude undesirable bacteria therefrom, and inoculated eggs produced thereby, are disclosed. In a preferred embodiment of the invention, a fertile bir...

N. A. Cox J. S. Bailey

1989-01-01

404

Characterising the biology of novel lytic bacteriophages infecting multidrug resistant Klebsiella pneumoniae  

PubMed Central

Background Members of the genus Klebsiella are among the leading microbial pathogens associated with nosocomial infection. The increased incidence of antimicrobial resistance in these species has propelled the need for alternate/combination therapeutic regimens to aid clinical treatment. Bacteriophage therapy forms one of these alternate strategies. Methods Electron microscopy, burst size, host range, sensitivity of phage particles to temperature, chloroform, pH, and restriction digestion of phage DNA were used to characterize Klebsiella phages. Results and conclusions Of the 32 isolated phages eight belonged to the family Myoviridae, eight to the Siphoviridae whilst the remaining 16 belonged to the Podoviridae. The host range of these phages was characterised against 254 clinical Enterobacteriaceae strains including multidrug resistant Klebsiella isolates producing extended-spectrum beta-lactamases (ESBLs). Based on their lytic potential, six of the phages were further characterised for burst size, physicochemical properties and sensitivity to restriction endonuclease digestion. In addition, five were fully sequenced. Multiple phage-encoded host resistance mechanisms were identified. The Siphoviridae phage genomes (KP16 and KP36) contained low numbers of host restriction sites similar to the strategy found in T7-like phages (KP32). In addition, phage KP36 encoded its own DNA adenine methyltransferase. The ?KMV-like KP34 phage was sensitive to all endonucleases used in this study. Dam methylation of KP34 DNA was detected although this was in the absence of an identifiable phage encoded methyltransferase. The Myoviridae phages KP15 and KP27 both carried Dam and Dcm methyltransferase genes and other anti-restriction mechanisms elucidated in previous studies. No other anti-restriction mechanisms were found, e.g. atypical nucleotides (hmC or glucosyl hmC), although Myoviridae phage KP27 encodes an unknown anti-restriction mechanism that needs further investigation.

2013-01-01

405

Surfactant Protein D Enhances Phagocytosis and Killing of Unencapsulated Phase Variants of Klebsiella pneumoniae  

PubMed Central

Pulmonary surfactant protein D (SP-D) is a collagenous C-type lectin (collectin) that is secreted into the alveoli and distal airways of the lung. We have studied the interactions of SP-D and alveolar macrophages with Klebsiella pneumoniae, a common cause of nosocomial pneumonia. SP-D does not agglutinate encapsulated K. pneumoniae but selectively agglutinates spontaneous, unencapsulated phase variants, such as Klebsiella strain K50-3OF, through interactions with their lipopolysaccharides (LPS). These effects are calcium dependent and inhibited with maltose but not lactose, consistent with involvement of the SP-D carbohydrate recognition domain. Precoating of K50-3OF with SP-D enhances the phagocytosis and killing of these organisms by rat alveolar macrophages in cell culture and stimulates the production of nitric oxide by the NR-8383 rat alveolar macrophage cell line. SP-D similarly enhances the NO response to K50-3OF LPS adsorbed to Latex beads under conditions where soluble LPS or SP-D, or soluble complexes of SP-D and LPS, do not stimulate NO production. Our studies demonstrate that interactions of SP-D with exposed arrays of Klebsiella LPS on a particulate surface can enhance the host defense activities of alveolar macrophages and suggest that activation of macrophages by SP-D requires binding to microorganisms or other particulate ligands. Because unencapsulated phase variants are likely to be responsible for the initial stages of tissue invasion and infection, we speculate that SP-D-mediated agglutination and/or opsonization of K. pneumoniae is an important defense mechanism for this respiratory pathogen in otherwise healthy individuals.

Ofek, Itzhak; Mesika, Adi; Kalina, Moshe; Keisari, Yona; Podschun, Ranier; Sahly, Hany; Chang, Donald; McGregor, David; Crouch, Erika

2001-01-01

406

Surfactant protein D enhances phagocytosis and killing of unencapsulated phase variants of Klebsiella pneumoniae.  

PubMed

Pulmonary surfactant protein D (SP-D) is a collagenous C-type lectin (collectin) that is secreted into the alveoli and distal airways of the lung. We have studied the interactions of SP-D and alveolar macrophages with Klebsiella pneumoniae, a common cause of nosocomial pneumonia. SP-D does not agglutinate encapsulated K. pneumoniae but selectively agglutinates spontaneous, unencapsulated phase variants, such as Klebsiella strain K50-3OF, through interactions with their lipopolysaccharides (LPS). These effects are calcium dependent and inhibited with maltose but not lactose, consistent with involvement of the SP-D carbohydrate recognition domain. Precoating of K50-3OF with SP-D enhances the phagocytosis and killing of these organisms by rat alveolar macrophages in cell culture and stimulates the production of nitric oxide by the NR-8383 rat alveolar macrophage cell line. SP-D similarly enhances the NO response to K50-3OF LPS adsorbed to Latex beads under conditions where soluble LPS or SP-D, or soluble complexes of SP-D and LPS, do not stimulate NO production. Our studies demonstrate that interactions of SP-D with exposed arrays of Klebsiella LPS on a particulate surface can enhance the host defense activities of alveolar macrophages and suggest that activation of macrophages by SP-D requires binding to microorganisms or other particulate ligands. Because unencapsulated phase variants are likely to be responsible for the initial stages of tissue invasion and infection, we speculate that SP-D-mediated agglutination and/or opsonization of K. pneumoniae is an important defense mechanism for this respiratory pathogen in otherwise healthy individuals. PMID:11119485

Ofek, I; Mesika, A; Kalina, M; Keisari, Y; Podschun, R; Sahly, H; Chang, D; McGregor, D; Crouch, E

2001-01-01

407

Outbreak of OXA-48-Positive Carbapenem-Resistant Klebsiella pneumoniae Isolates in France?  

PubMed Central

Seventeen Klebsiella pneumoniae isolates producing the OXA-48 carbapenemase, obtained from 10 patients hospitalized from April to June 2010, mostly in the medical intensive care unit of the Villeneuve-Saint-Georges Hospital in a suburb of Paris, France, were analyzed. Seven patients were infected, of whom five were treated at least with a carbapenem, and five patients died. Molecular analysis showed that the isolates belonged to a single clone that harbored a 70-kb plasmid carrying the blaOXA-48 gene and coproduced CTX-M-15 and TEM-1 ?-lactamases. This is the first reported outbreak of OXA-48-producing K. pneumoniae isolates in France.

Cuzon, Gaelle; Ouanich, Jocelyne; Gondret, Remy; Naas, Thierry; Nordmann, Patrice

2011-01-01

408

SHV-14, a Novel ?-Lactamase Variant in Klebsiella pneumoniae Isolates from Nijmegen, The Netherlands  

PubMed Central

Four ceftazidime-resistant isolates of a Klebsiella pneumoniae strain were collected from intensive care unit patients in Nijmegen, The Netherlands. These isolates had TEM-29 and SHV-14 ?-lactamases. SHV-14 is a novel variant, with two substitutions compared with the sequence of SHV-1: Ile8Phe and Arg43Ser. Its gene also had a silent C?T mutation at nucleotide 481. The SHV-14 enzyme had slightly higher Vmax rates than SHV-1 for oxyimino-aminothiazolyl cephalosporins, but this activity was insufficient for the enzyme to count as an extended-spectrum ?-lactamase.

Yuan, Meifang; Hall, Lucinda M. C.; Hoogkamp-Korstanje, Jaa; Livermore, David M.